diff --git a/.travis.yml b/.travis.yml
index 8c8c6699d3d9abddd65a3a224c2bceedc7d88348..b4b83fcdbc84ce0fb0c91c816ebc3c964acfa590 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -37,8 +37,8 @@ before_install:
   - if [[ "$JOB" == "check_style" ]]; then sudo ln -s /usr/bin/clang-format-3.8 /usr/bin/clang-format; fi
   # Paddle is using protobuf 3.1 currently. Protobuf 3.2 breaks the compatibility. So we specify the python
   # protobuf version.
-  - pip install numpy wheel 'protobuf==3.1' sphinx==1.5.6 recommonmark sphinx-rtd-theme==0.1.9 virtualenv pre-commit requests==2.9.2 LinkChecker
-  - pip install rarfile nltk==3.2.2 scipy==0.19.0 recordio matplotlib Pillow
+  - pip install -r $TRAVIS_BUILD_DIR/python/requirements.txt
+  - pip install wheel sphinx==1.5.6 recommonmark sphinx-rtd-theme==0.1.9 virtualenv pre-commit LinkChecker
   - curl https://glide.sh/get | bash
   - eval "$(GIMME_GO_VERSION=1.8.3 gimme)"
   - go get -u github.com/alecthomas/gometalinter
diff --git a/doc/design/auto_gradient_check.md b/doc/design/auto_gradient_check.md
new file mode 100644
index 0000000000000000000000000000000000000000..1f4d4ec16f7c395005e610751d95c10f5f3adf52
--- /dev/null
+++ b/doc/design/auto_gradient_check.md
@@ -0,0 +1,146 @@
+## Auto Gradient Checker Design
+
+## Backgraound：
+- Operator forward computing is easy to check if the result is right because it has a clear definition. **But** backpropagation is a notoriously difficult algorithm to debug and get right:
+  - 1. you should get the right backpropagation formula according to the forward computation.
+  - 2. you should implement it right in CPP.
+  - 3. it's difficult to prepare test data.
+
+- Auto gradient check gets a numeric gradient by forward Operator and use it as a reference of the backward Operator's result. It has several advantages:
+  - 1. numeric gradient checker only need forward operator.
+  - 2. user only need to prepare the input data for forward Operator.
+
+## Mathematical Theory
+The following two document from stanford has a detailed explanation of how to get numeric gradient and why it's useful.
+
+- [Gradient checking and advanced optimization(en)](http://deeplearning.stanford.edu/wiki/index.php/Gradient_checking_and_advanced_optimization)
+- [Gradient checking and advanced optimization(cn)](http://ufldl.stanford.edu/wiki/index.php/%E6%A2%AF%E5%BA%A6%E6%A3%80%E9%AA%8C%E4%B8%8E%E9%AB%98%E7%BA%A7%E4%BC%98%E5%8C%96)
+
+
+## Numeric Gradient Implementation
+### Python Interface
+```python
+def get_numeric_gradient(op,
+                         input_values,
+                         output_name,
+                         input_to_check,
+                         delta=0.005,
+                         local_scope=None):
+    """
+    Get Numeric Gradient for an operator's input.
+
+    :param op: C++ operator instance, could be an network
+    :param input_values: The input variables. Should be an dictionary, key is
+    variable name. Value is numpy array.
+    :param output_name: The final output variable name.
+    :param input_to_check: The input variable need to get gradient.
+    :param delta: The perturbation value for numeric gradient method. The
+    smaller delta is, the more accurate result will get. But if that delta is
+     too small, it could occur numerical stability problem.
+    :param local_scope: The local scope used for get_numeric_gradient.
+    :return: The gradient array in numpy format.
+    """
+```
+
+### Explaination:
+
+- Why need `output_name`
+  - One Operator may have multiple Output, you can get independent gradient from each Output. So user should set one output to calculate.
+
+- Why need `input_to_check`
+  - One operator may have multiple inputs. Gradient Op can calculate the gradient of these Inputs at the same time. But Numeric Gradient needs to calculate them one by one. So `get_numeric_gradient` is designed to calculate the gradient for one input. If you need to compute multiple inputs, you can call `get_numeric_gradient` multiple times.
+
+
+### Core Algorithm Implementation
+
+
+```python
+    # we only compute gradient of one element each time.
+    # we use a for loop to compute the gradient of every element.
+    for i in xrange(tensor_size):
+        # get one input element throw it's index i.
+        origin = tensor_to_check.get_float_element(i)
+
+        # add delta to it, run op and then get the sum of the result tensor.
+        x_pos = origin + delta
+        tensor_to_check.set_float_element(i, x_pos)
+        y_pos = get_output()
+
+        # plus delta to this element, run op and get the sum of the result tensor.
+        x_neg = origin - delta
+        tensor_to_check.set_float_element(i, x_neg)
+        y_neg = get_output()
+
+        # restore old value
+        tensor_to_check.set_float_element(i, origin)
+
+        # compute the gradient of this element and store it into a numpy array.
+        gradient_flat[i] = (y_pos - y_neg) / delta / 2
+
+    # reshape the gradient result to the shape of the source tensor.
+    return gradient_flat.reshape(tensor_to_check.get_dims())
+```
+
+## Auto Graident Checker Framework
+
+Each Operator Kernel has three kinds of Gradient:
+
+- 1. Numeric Gradient
+- 2. CPU Operator Gradient
+- 3. GPU Operator Gradient(if supported)
+
+Numeric Gradient Only relies on forward Operator. So we use Numeric Gradient as the reference value.
+
+- 1. calculate the numeric gradient.
+- 2. calculate CPU kernel Gradient with the backward Operator and compare it with the numeric gradient.
+- 3. calculate GPU kernel Gradient with the backward Operator and compare it with the numeric gradient.(if support GPU)
+
+#### Python Interface
+
+```python
+    def check_grad(self,
+                   forward_op,
+                   input_vars,
+                   inputs_to_check,
+                   output_name,
+                   no_grad_set=None,
+                   only_cpu=False,
+                   max_relative_error=0.005):
+        """
+        :param forward_op: used to create backward_op
+        :param input_vars: numpy value of input variable. The following
+            computation will use these variables.
+        :param inputs_to_check: inputs var names that should check gradient.
+        :param output_name: output name that used to
+        :param max_relative_error: The relative tolerance parameter.
+        :param no_grad_set: used when create backward ops
+        :param only_cpu: only compute and check gradient on cpu kernel.
+        :return:
+        """
+```
+
+### How to check if two numpy array is close enough?
+if `abs_numeric_grad` is nearly zero, then use abs error for numeric_grad, not relative
+
+```python
+numeric_grad = ...
+operator_grad = numpy.array(scope.find_var(grad_var_name(name)).get_tensor())
+
+abs_numeric_grad = numpy.abs(numeric_grad)
+# if abs_numeric_grad is nearly zero, then use abs error for numeric_grad, not relative
+# error.
+abs_numeric_grad[abs_numeric_grad < 1e-3] = 1
+
+diff_mat = numpy.abs(abs_numeric_grad - operator_grad) / abs_numeric_grad
+max_diff = numpy.max(diff_mat)
+```
+
+
+#### Notes：
+1，The Input data for auto gradient checker should be reasonable to avoid numeric problem.
+
+
+#### Refs:
+
+- [Gradient checking and advanced optimization(en)](http://deeplearning.stanford.edu/wiki/index.php/Gradient_checking_and_advanced_optimization)
+- [Gradient checking and advanced optimization(cn)](http://ufldl.stanford.edu/wiki/index.php/%E6%A2%AF%E5%BA%A6%E6%A3%80%E9%AA%8C%E4%B8%8E%E9%AB%98%E7%BA%A7%E4%BC%98%E5%8C%96)
diff --git a/paddle/framework/backward_test.cc b/paddle/framework/backward_test.cc
index 4136e2c36a083051fd9e5b16874a3d9c98ef9ed8..41bd77d265c5cdcc831e33c7904ea46359daee4f 100644
--- a/paddle/framework/backward_test.cc
+++ b/paddle/framework/backward_test.cc
@@ -30,6 +30,8 @@ using DeviceContext = platform::DeviceContext;
 
 class EmptyOp : public OperatorBase {
  public:
+  DEFINE_OPERATOR_CTOR(EmptyOp, OperatorBase)
+
   void InferShape(const Scope &scope) const override {}
   void Run(const Scope &scope, const DeviceContext &dev_ctx) const override {}
 };
diff --git a/paddle/framework/ddim.h b/paddle/framework/ddim.h
index b2d9fec047109fc53d281e2fbe9d2594a65a9201..95f294b62737be5c3eac39303148ac35da29fe7d 100644
--- a/paddle/framework/ddim.h
+++ b/paddle/framework/ddim.h
@@ -20,7 +20,6 @@ limitations under the License. */
 #include "paddle/framework/dim.h"
 #include "paddle/platform/enforce.h"
 #include "paddle/platform/variant.h"
-#include "unsupported/Eigen/CXX11/Tensor"
 
 namespace paddle {
 namespace framework {
diff --git a/paddle/framework/grad_op_builder.cc b/paddle/framework/grad_op_builder.cc
index f534b2c336645c652d78dc04a5b8bdc08bd3d082..b5c6bd3f56f3d8e16b58b76bd0215461c0f6d5ac 100644
--- a/paddle/framework/grad_op_builder.cc
+++ b/paddle/framework/grad_op_builder.cc
@@ -19,45 +19,44 @@ permissions and limitations under the License. */
 namespace paddle {
 namespace framework {
 
-class OpRegistry;
-
-using VarIndexMap = std::unordered_map<std::string, int>;
+typedef std::vector<int> Ints;
 
 enum class OpArgType { IN, OUT };
 
-static std::vector<int>* GetOpFormat(OperatorBase* op, const OpArgType& type) {
-  std::string key = type == OpArgType::IN ? "input_format" : "output_format";
-  return op->attrs_.count(key)
-             ? &boost::get<std::vector<int>>(op->attrs_.at(key))
-             : nullptr;
+const Ints* AttrFormat(const AttributeMap& attrs, const std::string& key) {
+  return (attrs.count(key) > 0) ? &boost::get<Ints>(attrs.at(key)) : nullptr;
 }
 
-static const std::vector<int>* GetOpFormat(const OperatorBase* op,
-                                           const OpArgType& type) {
-  std::string key = type == OpArgType::IN ? "input_format" : "output_format";
-  return op->attrs_.count(key)
-             ? &boost::get<std::vector<int>>(op->attrs_.at(key))
-             : nullptr;
+Ints* AttrFormat(AttributeMap& attrs, const std::string& key) {
+  return (attrs.count(key) > 0) ? &boost::get<Ints>(attrs.at(key)) : nullptr;
 }
 
-static void TransOpArg(const OperatorBase* src_op, OperatorBase* dst_op,
-                       const OpArgType& src_type, const OpArgType& dst_type,
+static void TransOpArg(const OperatorBase* src_op,
+                       std::vector<std::string>& grad_inputs,
+                       std::vector<std::string>& grad_outputs,
+                       AttributeMap& grad_attrs,
+                       std::unordered_map<std::string, int>& grad_idxs,
+                       const std::string& src_type, const std::string& dst_type,
                        int& idx, bool is_grad) {
   const std::vector<std::string>& src_inout =
-      src_type == OpArgType::IN ? src_op->inputs_ : src_op->outputs_;
-  const std::vector<int>* src_format = GetOpFormat(src_op, src_type);
+      (src_type == "input_format") ? src_op->inputs_ : src_op->outputs_;
+
+  const std::vector<int>* src_format = AttrFormat(src_op->Attrs(), src_type);
 
   std::vector<std::string>& dst_inout =
-      dst_type == OpArgType::IN ? dst_op->inputs_ : dst_op->outputs_;
-  std::vector<int>* dst_format = GetOpFormat(dst_op, dst_type);
+      (dst_type == "input_format") ? grad_inputs : grad_outputs;
+
+  std::vector<int>* dst_format = AttrFormat(grad_attrs, dst_type);
+
   const OpProto& proto = *(OpRegistry::op_info_map().at(src_op->type_).proto_);
+
   const auto& src_arg_list =
-      src_type == OpArgType::IN ? proto.inputs() : proto.outputs();
+      (src_type == "input_format") ? proto.inputs() : proto.outputs();
 
   for (const auto& arg : src_arg_list) {
     std::string src_name = arg.name();
     std::string dst_name = is_grad ? src_name + kGradVarSuffix : src_name;
-    (*dst_op->in_out_idxs_)[dst_name] = idx++;
+    grad_idxs[dst_name] = idx++;
     int src_arg_idx = src_op->in_out_idxs_->at(src_name);
     int src_begin =
         src_format == nullptr ? src_arg_idx : src_format->at(src_arg_idx);
@@ -82,28 +81,44 @@ OperatorBase* BuildGradOp(const OperatorBase* op) {
   std::string grad_op_type = it->second.grad_op_type_;
   PADDLE_ENFORCE(!grad_op_type.empty(), "'%s' has no gradient operator.",
                  op->type_);
+
+  AttributeMap grad_attrs(op->Attrs());
+  grad_attrs.erase("input_format");
+  grad_attrs.erase("output_format");
+  if (op->Attrs().count("input_format") > 0) {
+    grad_attrs["output_format"] = std::vector<int>({0});
+  }
+  if (op->Attrs().count("input_format") > 0 ||
+      op->Attrs().count("output_format") > 0) {
+    grad_attrs["input_format"] = std::vector<int>({0});
+  }
+
+  std::vector<std::string> grad_inputs, grad_outputs;
+
+  using VarIndexMap = std::unordered_map<std::string, int>;
+  VarIndexMap* grad_idxs = new VarIndexMap;
+  int in_idx = 0;
+  int out_idx = 0;
+  TransOpArg(op, grad_inputs, grad_outputs, grad_attrs, *grad_idxs,
+             "input_format", "input_format", in_idx, false);  // I
+  TransOpArg(op, grad_inputs, grad_outputs, grad_attrs, *grad_idxs,
+             "output_format", "input_format", in_idx, false);  // G
+  TransOpArg(op, grad_inputs, grad_outputs, grad_attrs, *grad_idxs,
+             "output_format", "input_format", in_idx, true);  // OG
+  TransOpArg(op, grad_inputs, grad_outputs, grad_attrs, *grad_idxs,
+             "input_format", "output_format", out_idx, true);  // IG
+
   it = OpRegistry::op_info_map().find(grad_op_type);
   PADDLE_ENFORCE(it != OpRegistry::op_info_map().end(),
                  "'%s' has not been registered.", grad_op_type);
   OperatorBase* grad_op = it->second.creator_();
+
   grad_op->type_ = grad_op_type;
-  grad_op->attrs_ = op->attrs_;
-  grad_op->attrs_.erase("input_format");
-  grad_op->attrs_.erase("output_format");
-  if (GetOpFormat(op, OpArgType::IN) != nullptr) {
-    grad_op->attrs_["output_format"] = std::vector<int>({0});
-  }
-  if (GetOpFormat(op, OpArgType::IN) != nullptr ||
-      GetOpFormat(op, OpArgType::OUT) != nullptr) {
-    grad_op->attrs_["input_format"] = std::vector<int>({0});
-  }
-  grad_op->in_out_idxs_.reset(new VarIndexMap());
-  int in_idx = 0;
-  int out_idx = 0;
-  TransOpArg(op, grad_op, OpArgType::IN, OpArgType::IN, in_idx, false);   // I
-  TransOpArg(op, grad_op, OpArgType::OUT, OpArgType::IN, in_idx, false);  // G
-  TransOpArg(op, grad_op, OpArgType::OUT, OpArgType::IN, in_idx, true);   // OG
-  TransOpArg(op, grad_op, OpArgType::IN, OpArgType::OUT, out_idx, true);  // IG
+  grad_op->inputs_ = grad_inputs;
+  grad_op->outputs_ = grad_outputs;
+  grad_op->attrs_ = grad_attrs;
+  grad_op->in_out_idxs_.reset(grad_idxs);
+
   return grad_op;
 }
 
diff --git a/paddle/framework/op_registry.h b/paddle/framework/op_registry.h
index 080a7149bb0e23411dee3a363c73b8b5975d8941..a561b5f48e27b80ed38a08b584808fade4e74f31 100644
--- a/paddle/framework/op_registry.h
+++ b/paddle/framework/op_registry.h
@@ -70,18 +70,18 @@ class OpProtoAndCheckerMaker {
 
   VariableBuilder AddInput(const std::string& name,
                            const std::string& comment) {
-    auto input = proto_->mutable_inputs()->Add();
-    *input->mutable_name() = name;
-    *input->mutable_comment() = comment;
+    VarProto* input = proto_->add_inputs();
+    input->set_name(name);
+    input->set_comment(comment);
     return VariableBuilder{input, [=] { this->SetHasMultipleInput(); },
                            nullptr};
   }
 
   VariableBuilder AddOutput(const std::string& name,
                             const std::string& comment) {
-    auto output = proto_->mutable_outputs()->Add();
-    *output->mutable_name() = name;
-    *output->mutable_comment() = comment;
+    VarProto* output = proto_->add_outputs();
+    output->set_name(name);
+    output->set_comment(comment);
     return VariableBuilder{output, [=] { this->SetHasMultipleOutput(); },
                            [=] { this->SetHasTemporaryOutput(); }};
   }
@@ -90,17 +90,15 @@ class OpProtoAndCheckerMaker {
   TypedAttrChecker<T>& AddAttr(const std::string& name,
                                const std::string& comment,
                                bool generated = false) {
-    auto attr = proto_->mutable_attrs()->Add();
-    *attr->mutable_name() = name;
-    *attr->mutable_comment() = comment;
+    AttrProto* attr = proto_->add_attrs();
+    attr->set_name(name);
+    attr->set_comment(comment);
     attr->set_generated(generated);
     attr->set_type(AttrTypeID<T>());
     return op_checker_->AddAttrChecker<T>(name);
   }
 
-  void AddComment(const std::string& comment) {
-    *(proto_->mutable_comment()) = comment;
-  }
+  void AddComment(const std::string& comment) { proto_->set_comment(comment); }
 
  private:
   void SetHasMultiple(const std::string& in_out, bool* flag) {
@@ -207,7 +205,7 @@ class OpRegistry {
       op_info.checker_ = new OpAttrChecker;
       auto maker = ProtoMakerType(op_info.proto_, op_info.checker_);
       maker.Validate();
-      *op_info.proto_->mutable_type() = op_type;
+      op_info.proto_->set_type(op_type);
       PADDLE_ENFORCE(
           op_info.proto_->IsInitialized(),
           "Fail to initialize %s's OpProto, because %s is not initialized",
diff --git a/paddle/framework/op_registry_test.cc b/paddle/framework/op_registry_test.cc
index 6f21ffc8a4b701b612e4a6f50f1d414bbbfbadb1..f7782e90912a19228066f3719c83277ec00db322 100644
--- a/paddle/framework/op_registry_test.cc
+++ b/paddle/framework/op_registry_test.cc
@@ -7,6 +7,8 @@ namespace paddle {
 namespace framework {
 class CosineOp : public OperatorBase {
  public:
+  DEFINE_OPERATOR_CTOR(CosineOp, OperatorBase)
+
   void Run(const Scope& scope,
            const platform::DeviceContext& dev_ctx) const override {}
   void InferShape(const Scope& scope) const override {}
@@ -27,6 +29,8 @@ class CosineOpProtoAndCheckerMaker : public OpProtoAndCheckerMaker {
 
 class MyTestOp : public OperatorBase {
  public:
+  DEFINE_OPERATOR_CTOR(MyTestOp, OperatorBase)
+
   void InferShape(const Scope& scope) const override {}
   void Run(const Scope& scope,
            const platform::DeviceContext& dev_ctx) const override {}
diff --git a/paddle/framework/operator.h b/paddle/framework/operator.h
index 13308e0dae5d8d0ab2b50b90a8b8d709c8e9f8f3..058fe3282ffabb1a3088208599ced8278f77da00 100644
--- a/paddle/framework/operator.h
+++ b/paddle/framework/operator.h
@@ -63,6 +63,17 @@ class ExecutionContext;
  */
 class OperatorBase {
  public:
+  OperatorBase() {}  // TODO(yi): This constructor is to be removed.
+  OperatorBase(const std::string& type, const std::vector<std::string>& inputs,
+               const std::vector<std::string>& outputs,
+               const AttributeMap& attrs,
+               std::unordered_map<std::string, int>* in_out_idxs)
+      : type_(type),
+        inputs_(inputs),
+        outputs_(outputs),
+        attrs_(attrs),
+        in_out_idxs_(in_out_idxs) {}
+
   virtual ~OperatorBase() {}
 
   template <typename T>
@@ -109,6 +120,9 @@ class OperatorBase {
   const std::vector<std::string> Inputs() const { return inputs_; }
   const std::vector<std::string> Outputs() const { return outputs_; }
   const AttributeMap& Attrs() const { return attrs_; }
+  const std::unordered_map<std::string, int>* InOutIdx() const {
+    return in_out_idxs_.get();
+  }
 
  public:
   std::string type_;
@@ -127,6 +141,8 @@ class OperatorBase {
 
 class NOP : public OperatorBase {
  public:
+  DEFINE_OPERATOR_CTOR(NOP, OperatorBase)
+
   void InferShape(const Scope& scope) const override {}
   void Run(const Scope& scope,
            const platform::DeviceContext& dev_ctx) const override {}
@@ -293,6 +309,14 @@ class OpKernel {
 
 class OperatorWithKernel : public OperatorBase {
  public:
+  OperatorWithKernel() {}  // TODO(yi): This constructor is to be removed.
+  OperatorWithKernel(const std::string& type,
+                     const std::vector<std::string>& inputs,
+                     const std::vector<std::string>& outputs,
+                     const AttributeMap& attrs,
+                     std::unordered_map<std::string, int>* in_out_idxs)
+      : OperatorBase(type, inputs, outputs, attrs, in_out_idxs) {}
+
   struct OpKernelKey {
     platform::Place place_;
 
@@ -342,5 +366,15 @@ class OperatorWithKernel : public OperatorBase {
   virtual void InferShape(const InferShapeContext& ctx) const = 0;
 };
 
+#define DEFINE_OPERATOR_CTOR(Class, ParentClass)                         \
+ public:                                                                 \
+  Class() { /* TODO(yi): This constructor is to be removed. */           \
+  }                                                                      \
+  Class(const std::string& type, const std::vector<std::string>& inputs, \
+        const std::vector<std::string>& outputs,                         \
+        const ::paddle::framework::AttributeMap& attrs,                  \
+        std::unordered_map<std::string, int>* in_out_idxs)               \
+      : ParentClass(type, inputs, outputs, attrs, in_out_idxs) {}
+
 }  // namespace framework
 }  // namespace paddle
diff --git a/paddle/framework/operator_test.cc b/paddle/framework/operator_test.cc
index 3887cadc60efe5061dbc9a496b1d7a334b2cb3db..aadc599a4270dd8801dedcb93060fe8d71f12430 100644
--- a/paddle/framework/operator_test.cc
+++ b/paddle/framework/operator_test.cc
@@ -23,6 +23,8 @@ static int op_run_num = 0;
 
 class OpWithoutKernelTest : public OperatorBase {
  public:
+  DEFINE_OPERATOR_CTOR(OpWithoutKernelTest, OperatorBase)
+
   void Init() override { x = 1; }
   void InferShape(const Scope& scope) const override {}
   void Run(const Scope& scope,
@@ -98,6 +100,8 @@ class OpKernelTestProtoAndCheckerMaker : public OpProtoAndCheckerMaker {
 static int cpu_kernel_run_num = 0;
 
 class OpWithKernelTest : public OperatorWithKernel {
+ public:
+  DEFINE_OPERATOR_CTOR(OpWithKernelTest, OperatorWithKernel)
  protected:
   void InferShape(const framework::InferShapeContext& ctx) const override {}
 };
@@ -117,6 +121,8 @@ class CPUKernelTest : public OpKernel {
 // multiple inputs test
 class OperatorMultiInputsTest : public OperatorBase {
  public:
+  DEFINE_OPERATOR_CTOR(OperatorMultiInputsTest, OperatorBase)
+
   void Init() override { x = 1; }
   void InferShape(const Scope& scope) const override {}
   void Run(const Scope& scope,
diff --git a/paddle/operators/add_op.cc b/paddle/operators/add_op.cc
index 447e7b39150dba468b9fa6ffc69d1c19a39355b9..47f3b527e329bacb2a76c18467ebf2f11c2f89cb 100644
--- a/paddle/operators/add_op.cc
+++ b/paddle/operators/add_op.cc
@@ -18,6 +18,7 @@ namespace paddle {
 namespace operators {
 
 class AddOp : public framework::OperatorWithKernel {
+  DEFINE_OPERATOR_CTOR(AddOp, framework::OperatorWithKernel)
  protected:
   void InferShape(const framework::InferShapeContext &ctx) const override {
     PADDLE_ENFORCE_EQ(ctx.InputSize(), 2);
@@ -47,6 +48,7 @@ The equation is: Out = X + Y
 };
 
 class AddOpGrad : public framework::OperatorWithKernel {
+  DEFINE_OPERATOR_CTOR(AddOpGrad, framework::OperatorWithKernel)
  protected:
   void InferShape(const framework::InferShapeContext &ctx) const override {}
 };
diff --git a/paddle/operators/cross_entropy_op.cc b/paddle/operators/cross_entropy_op.cc
index 3dcaccd7565e95edafd7281bdb4222d0980926d2..2db30a3bc1df91256c20126458736cdf8673ece6 100644
--- a/paddle/operators/cross_entropy_op.cc
+++ b/paddle/operators/cross_entropy_op.cc
@@ -18,6 +18,7 @@ namespace paddle {
 namespace operators {
 
 class OnehotCrossEntropyOp : public framework::OperatorWithKernel {
+  DEFINE_OPERATOR_CTOR(OnehotCrossEntropyOp, framework::OperatorWithKernel)
  protected:
   void InferShape(const framework::InferShapeContext &ctx) const override {
     PADDLE_ENFORCE_EQ(ctx.InputSize(), 2,
@@ -38,6 +39,8 @@ class OnehotCrossEntropyOp : public framework::OperatorWithKernel {
 };
 
 class OnehotCrossEntropyGradientOp : public framework::OperatorWithKernel {
+  DEFINE_OPERATOR_CTOR(OnehotCrossEntropyGradientOp,
+                       framework::OperatorWithKernel)
  protected:
   void InferShape(const framework::InferShapeContext &ctx) const override {
     auto X_grad = ctx.Output<Tensor>(framework::GradVarName("X"));
diff --git a/paddle/operators/fill_zeros_like_op.cc b/paddle/operators/fill_zeros_like_op.cc
index d6fd368b078c8e674a509448703ff77a856e9e20..48e3506d556469e414ed6550b60148115242f9a1 100644
--- a/paddle/operators/fill_zeros_like_op.cc
+++ b/paddle/operators/fill_zeros_like_op.cc
@@ -18,6 +18,7 @@ namespace paddle {
 namespace operators {
 
 class FillZerosLikeOp : public framework::OperatorWithKernel {
+  DEFINE_OPERATOR_CTOR(FillZerosLikeOp, framework::OperatorWithKernel)
  protected:
   void InferShape(const framework::InferShapeContext &ctx) const override {
     PADDLE_ENFORCE_EQ(ctx.InputSize(), 1UL,
diff --git a/paddle/operators/gaussian_random_op.cc b/paddle/operators/gaussian_random_op.cc
index 0bbbeaa08a11f05a9eae63d0235ea8b0feb24062..b826a4694333c0700993fbf4e78d68561affd2c0 100644
--- a/paddle/operators/gaussian_random_op.cc
+++ b/paddle/operators/gaussian_random_op.cc
@@ -43,6 +43,7 @@ class GaussianRandomKernel : public framework::OpKernel {
 };
 
 class GaussianRandomOp : public framework::OperatorWithKernel {
+  DEFINE_OPERATOR_CTOR(GaussianRandomOp, framework::OperatorWithKernel)
  protected:
   void InferShape(const framework::InferShapeContext& context) const override {
     auto* tensor = context.Output<framework::Tensor>(0);
diff --git a/paddle/operators/mean_op.cc b/paddle/operators/mean_op.cc
index c41208014a7bf5b7d30b070a931b9a477ead026d..3bdd71d2e514728fca79958abaf5f93fc161ac1a 100644
--- a/paddle/operators/mean_op.cc
+++ b/paddle/operators/mean_op.cc
@@ -18,6 +18,7 @@ namespace paddle {
 namespace operators {
 
 class MeanOp : public framework::OperatorWithKernel {
+  DEFINE_OPERATOR_CTOR(MeanOp, framework::OperatorWithKernel)
  protected:
   void InferShape(const framework::InferShapeContext &ctx) const override {
     PADDLE_ENFORCE_EQ(ctx.InputSize(), 1, "Input size of AddOp must be one");
@@ -39,6 +40,7 @@ class MeanOpMaker : public framework::OpProtoAndCheckerMaker {
 };
 
 class MeanGradOp : public framework::OperatorWithKernel {
+  DEFINE_OPERATOR_CTOR(MeanGradOp, framework::OperatorWithKernel)
  protected:
   void InferShape(const framework::InferShapeContext &ctx) const override {
     ctx.Output<Tensor>(framework::GradVarName("X"))
diff --git a/paddle/operators/mul_op.cc b/paddle/operators/mul_op.cc
index 0c4547f04d3492e473afc11069b9f62616acb80a..db77228245590d9e2405820384e2db62595546f1 100644
--- a/paddle/operators/mul_op.cc
+++ b/paddle/operators/mul_op.cc
@@ -18,6 +18,7 @@ namespace paddle {
 namespace operators {
 
 class MulOp : public framework::OperatorWithKernel {
+  DEFINE_OPERATOR_CTOR(MulOp, framework::OperatorWithKernel)
  protected:
   void InferShape(const framework::InferShapeContext &ctx) const override {
     PADDLE_ENFORCE(ctx.InputSize() == 2, "The mul op must take two inputs");
@@ -53,6 +54,7 @@ The equation is: Out = X * Y
 };
 
 class MulOpGrad : public framework::OperatorWithKernel {
+  DEFINE_OPERATOR_CTOR(MulOpGrad, framework::OperatorWithKernel)
  protected:
   void InferShape(const framework::InferShapeContext &ctx) const override {}
   std::string DebugString() const override {
diff --git a/paddle/operators/net_op.h b/paddle/operators/net_op.h
index 792b336675fc97659d9a23358cf3d48ede56e54e..24c9e61c66933c6be5bf44b3537e00b70a33922f 100644
--- a/paddle/operators/net_op.h
+++ b/paddle/operators/net_op.h
@@ -35,6 +35,8 @@ namespace operators {
  */
 class NetOp : public framework::OperatorBase {
  public:
+  DEFINE_OPERATOR_CTOR(NetOp, framework::OperatorBase)
+
   /**
    * Infer all the operators' input and output variables' shapes, will be called
    * before every mini-batch
diff --git a/paddle/operators/net_op_test.cc b/paddle/operators/net_op_test.cc
index 76bf79f9b51fd759da2d02cd90fa458a32be4178..0d5c3de798d0b580860d24ea9a61a6a4ede5d0ab 100644
--- a/paddle/operators/net_op_test.cc
+++ b/paddle/operators/net_op_test.cc
@@ -12,6 +12,8 @@ static int run_cnt = 0;
 
 class TestOp : public framework::OperatorBase {
  public:
+  DEFINE_OPERATOR_CTOR(TestOp, framework::OperatorBase)
+
   void InferShape(const Scope& scope) const override { ++infer_shape_cnt; }
   void Run(const Scope& scope,
            const platform::DeviceContext& dev_ctx) const override {
@@ -21,6 +23,8 @@ class TestOp : public framework::OperatorBase {
 
 class EmptyOp : public framework::OperatorBase {
  public:
+  DEFINE_OPERATOR_CTOR(EmptyOp, framework::OperatorBase)
+
   void InferShape(const Scope& scope) const override {}
   void Run(const Scope& scope, const DeviceContext& dev_ctx) const override {}
 };
diff --git a/paddle/operators/recurrent_op.h b/paddle/operators/recurrent_op.h
index d1e60fed9cef3c6dccba3ad498fc3658a177b3f7..fdd9d005378e63b8d44803fb2b4be83d134c6a5b 100644
--- a/paddle/operators/recurrent_op.h
+++ b/paddle/operators/recurrent_op.h
@@ -100,6 +100,7 @@ class RecurrentGradientAlgorithm {
 };
 
 class RecurrentOp final : public framework::OperatorBase {
+  DEFINE_OPERATOR_CTOR(RecurrentOp, framework::OperatorBase)
  public:
   void Init() override;
 
diff --git a/paddle/operators/rowwise_add_op.cc b/paddle/operators/rowwise_add_op.cc
index 262a4127ef98a957547609f1aa1eb4105b0b5e0e..01f287377f5d16ab88e34b5797ede33185a6d96c 100644
--- a/paddle/operators/rowwise_add_op.cc
+++ b/paddle/operators/rowwise_add_op.cc
@@ -18,6 +18,7 @@ namespace paddle {
 namespace operators {
 
 class RowWiseAddOp : public framework::OperatorWithKernel {
+  DEFINE_OPERATOR_CTOR(RowWiseAddOp, framework::OperatorWithKernel)
  protected:
   void InferShape(const framework::InferShapeContext &ctx) const override {
     PADDLE_ENFORCE(ctx.InputSize() == 2UL,
diff --git a/paddle/operators/sgd_op.cc b/paddle/operators/sgd_op.cc
index 94d0fe0466a95daf87bc850ce6a356bd327cf30d..6c6ed041afaf849b885d1d132398049cfbf95c79 100644
--- a/paddle/operators/sgd_op.cc
+++ b/paddle/operators/sgd_op.cc
@@ -18,6 +18,7 @@ namespace paddle {
 namespace operators {
 
 class SGDOp : public framework::OperatorWithKernel {
+  DEFINE_OPERATOR_CTOR(SGDOp, framework::OperatorWithKernel)
  protected:
   void InferShape(const framework::InferShapeContext &ctx) const override {
     PADDLE_ENFORCE_EQ(ctx.InputSize(), 2, "Input size of SGDOp must be two");
diff --git a/paddle/operators/sigmoid_op.cc b/paddle/operators/sigmoid_op.cc
index 4f3a880b40d4e06ca1c41645a8b35f5958070b60..c10cda8d6f2a3f4eb400ff345d6efec452bae983 100644
--- a/paddle/operators/sigmoid_op.cc
+++ b/paddle/operators/sigmoid_op.cc
@@ -18,6 +18,7 @@ namespace paddle {
 namespace operators {
 
 class SigmoidOp : public framework::OperatorWithKernel {
+  DEFINE_OPERATOR_CTOR(SigmoidOp, framework::OperatorWithKernel)
  protected:
   void InferShape(const framework::InferShapeContext &ctx) const override {
     PADDLE_ENFORCE(ctx.InputSize() == 1, "Sigmoid Op only have one input");
@@ -38,6 +39,7 @@ class SigmoidOpMaker : public framework::OpProtoAndCheckerMaker {
 };
 
 class SigmoidOpGrad : public framework::OperatorWithKernel {
+  DEFINE_OPERATOR_CTOR(SigmoidOpGrad, framework::OperatorWithKernel)
  protected:
   void InferShape(const framework::InferShapeContext &ctx) const override {
     ctx.Output<Tensor>(0)->Resize(ctx.Input<Tensor>(0)->dims());
diff --git a/paddle/operators/softmax_op.cc b/paddle/operators/softmax_op.cc
index 99bc5b77d1e3d59a37fd8f96b55f760e6f9be88e..7b681accc811a3f2afe4109ca17f2eda37c58ec7 100644
--- a/paddle/operators/softmax_op.cc
+++ b/paddle/operators/softmax_op.cc
@@ -18,6 +18,7 @@ namespace paddle {
 namespace operators {
 
 class SoftmaxOp : public framework::OperatorWithKernel {
+  DEFINE_OPERATOR_CTOR(SoftmaxOp, framework::OperatorWithKernel)
  protected:
   void InferShape(const framework::InferShapeContext &ctx) const override {
     PADDLE_ENFORCE_EQ(ctx.InputSize(), 1UL,
@@ -42,6 +43,7 @@ class SoftmaxOpMaker : public framework::OpProtoAndCheckerMaker {
 };
 
 class SoftmaxOpGrad : public framework::OperatorWithKernel {
+  DEFINE_OPERATOR_CTOR(SoftmaxOpGrad, framework::OperatorWithKernel)
  protected:
   void InferShape(const framework::InferShapeContext &ctx) const override {
     PADDLE_ENFORCE_EQ(ctx.InputSize(), 3UL,
diff --git a/paddle/operators/uniform_random_op.cc b/paddle/operators/uniform_random_op.cc
index 37ec7fe427097d808d948737e40be41e310bef0f..9410693ccec8b463f002693e75dbc8dae0271d52 100644
--- a/paddle/operators/uniform_random_op.cc
+++ b/paddle/operators/uniform_random_op.cc
@@ -46,6 +46,7 @@ class CPUUniformRandomKernel : public framework::OpKernel {
 };
 
 class UniformRandomOp : public framework::OperatorWithKernel {
+  DEFINE_OPERATOR_CTOR(UniformRandomOp, framework::OperatorWithKernel)
  protected:
   void InferShape(const framework::InferShapeContext& ctx) const override {
     PADDLE_ENFORCE(GetAttr<float>("min") < GetAttr<float>("max"),
diff --git a/paddle/trainer/NewRemoteParameterUpdater.cpp b/paddle/trainer/NewRemoteParameterUpdater.cpp
index cccb7e7cddda18a88355b0217c421ef3e2a21d92..35dcb235e7e8b65f7d1623a1ec66d963b1283385 100644
--- a/paddle/trainer/NewRemoteParameterUpdater.cpp
+++ b/paddle/trainer/NewRemoteParameterUpdater.cpp
@@ -68,7 +68,7 @@ void NewRemoteParameterUpdater::init(
     LOG(INFO) << "paddle_begin_init_params start";
     // NOTE: convert V1 OptimizatioinConfig proto to V2 OptimizerConfig.
     // This makes golang pserver compatible with handy V1 demos.
-    // TODO: Refine or remove these ugly converting lines
+    // TODO(wuyi): Refine or remove these ugly converting lines
     OptimizerConfig optimizerConfigV2;
     if (trainerConfig_.learning_method() == "momentum") {
       optimizerConfigV2.set_optimizer(paddle::OptimizerConfig::SGD);
diff --git a/python/paddle/v2/framework/tests/gradient_checker.py b/python/paddle/v2/framework/tests/gradient_checker.py
index aacc5e88feeb65e08093a35ef85837c916cfd39e..015e832e82560bb8b3518cbdf605c705d77cdd99 100644
--- a/python/paddle/v2/framework/tests/gradient_checker.py
+++ b/python/paddle/v2/framework/tests/gradient_checker.py
@@ -73,21 +73,35 @@ def get_numeric_gradient(op,
     def product(dim):
         return reduce(lambda a, b: a * b, dim, 1)
 
+    # get the input tensor that we want to get it's numeric gradient.
     tensor_to_check = local_scope.find_var(input_to_check).get_tensor()
     tensor_size = product(tensor_to_check.get_dims())
+    # prepare a numpy array to store the gradient.
     gradient_flat = numpy.zeros(shape=(tensor_size, ), dtype='float32')
+
+    # we only compute gradient of one element each time.
+    # we use a for loop to compute the gradient of every element.
     for i in xrange(tensor_size):
+        # get one input element throw it's index i.
         origin = tensor_to_check.get_float_element(i)
+
+        # add delta to it, run op and then get the sum of the result tensor.
         x_pos = origin + delta
         tensor_to_check.set_float_element(i, x_pos)
         y_pos = get_output()
 
+        # plus delta to this element, run op and get the sum of the result tensor.
         x_neg = origin - delta
         tensor_to_check.set_float_element(i, x_neg)
         y_neg = get_output()
 
-        tensor_to_check.set_float_element(i, origin)  # restore old value
+        # restore old value
+        tensor_to_check.set_float_element(i, origin)
+
+        # compute the gradient of this element and store it into a numpy array.
         gradient_flat[i] = (y_pos - y_neg) / delta / 2
+
+    # reshape the gradient result to the shape of the source tensor.
     return gradient_flat.reshape(tensor_to_check.get_dims())
 
 
diff --git a/python/requirements.txt b/python/requirements.txt
new file mode 100644
index 0000000000000000000000000000000000000000..3df822bd76d2a64a0a35f84b4ec309ce7150c221
--- /dev/null
+++ b/python/requirements.txt
@@ -0,0 +1,9 @@
+requests==2.9.2
+numpy>=1.12
+protobuf==3.1
+recordio
+matplotlib
+rarfile
+scipy>=0.19.0
+Pillow
+nltk>=3.2.2
diff --git a/python/setup.py.in b/python/setup.py.in
index 4110c983180937e86716324f8c92c37b7d2cc3ea..38728aa2fd77cf3c882479ed83e99688b9ffa541 100644
--- a/python/setup.py.in
+++ b/python/setup.py.in
@@ -1,5 +1,4 @@
 from setuptools import setup, Distribution
-
 class BinaryDistribution(Distribution):
     def has_ext_modules(foo):
         return True
@@ -18,15 +17,8 @@ packages=['paddle',
           'paddle.v2.framework.proto',
           'py_paddle']
 
-setup_requires=["requests",
-                "numpy>=1.12",
-                "protobuf==3.1",
-                "recordio",
-                "matplotlib",
-                "rarfile",
-                "scipy>=0.19.0",
-                "Pillow",
-                "nltk>=3.2.2"]
+with open('@PADDLE_SOURCE_DIR@/python/requirements.txt') as f:
+    setup_requires = f.read().splitlines()
 
 if '${CMAKE_SYSTEM_PROCESSOR}' not in ['arm', 'armv7-a', 'aarch64']:
     setup_requires+=["opencv-python"]