diff --git a/paddle/optimizer/Tensor.h b/paddle/optimizer/Tensor.h
index 9f68877e3ba9ef7ca740eab6a5d208f97c130f87..a00a59bc6af4d714a8250f0267017d1bbfc19108 100644
--- a/paddle/optimizer/Tensor.h
+++ b/paddle/optimizer/Tensor.h
@@ -46,7 +46,7 @@ protected:
 };
 
 // TODO(zhihong): design problem of dynamic datatype, need to fix it
-typedef TensorT<real> Tensor;
+typedef TensorT<float> Tensor;
 
 }  // namespace optimizer
 }  // namespace paddle
diff --git a/paddle/optimizer/adadelta_optimizer.h b/paddle/optimizer/adadelta_optimizer.h
index d17fae6b70a65b3ec4d81de2063e42a5dafab53c..4f6137cf2e5aca82a6f0b5afee8afec699bfe313 100644
--- a/paddle/optimizer/adadelta_optimizer.h
+++ b/paddle/optimizer/adadelta_optimizer.h
@@ -8,7 +8,13 @@ namespace optimizer {
 class AdadeltaOptimizer : public ParameterOptimizer {
 public:
   AdadeltaOptimizer(double rho, double epsilon, double decay, LrPolicy *lr)
-      : ParameterOptimizer(lr), rho_(rho), epsilon_(epsilon), decay_(decay) {}
+      : ParameterOptimizer(lr),
+        accum_gradient_(nullptr),
+        accum_delta_(nullptr),
+        update_delta_(nullptr),
+        rho_(rho),
+        epsilon_(epsilon),
+        decay_(decay) {}
   ~AdadeltaOptimizer() {
     if (accum_gradient_) delete accum_gradient_;
     if (accum_delta_) delete accum_delta_;
@@ -16,13 +22,11 @@ public:
   }
   void Update(const Tensor *gradient);
   void set_weight(Tensor *p);
-  real *get_weight() const;
 
 private:
   Tensor *accum_gradient_;
   Tensor *accum_delta_;
   Tensor *update_delta_;
-
   double rho_;
   double epsilon_;
   double decay_;
diff --git a/paddle/optimizer/adagrad_optimizer.h b/paddle/optimizer/adagrad_optimizer.h
index 6c00665c86c05d5c4c266e1ee8c1672d1224beb1..1b05e99754bfb29ed95b29450310dc7888f9d1d1 100644
--- a/paddle/optimizer/adagrad_optimizer.h
+++ b/paddle/optimizer/adagrad_optimizer.h
@@ -8,13 +8,15 @@ namespace optimizer {
 class AdagradOptimizer : public ParameterOptimizer {
 public:
   AdagradOptimizer(double epsilon, double decay, LrPolicy *lr)
-      : ParameterOptimizer(lr), epsilon_(epsilon), decay_(decay) {}
+      : ParameterOptimizer(lr),
+        accum_gradient_(nullptr),
+        epsilon_(epsilon),
+        decay_(decay) {}
   ~AdagradOptimizer() {
     if (accum_gradient_) delete accum_gradient_;
   }
   void Update(const Tensor *gradient);
   void set_weight(Tensor *p);
-  real *get_weight() const;
 
 private:
   Tensor *accum_gradient_;
diff --git a/paddle/optimizer/adam_optimizer.h b/paddle/optimizer/adam_optimizer.h
index 718039e451492f90c2be8db5d5def3ec5fdfb7a6..840927e6c7d59ee3d51e284fb2593508e812ffbd 100644
--- a/paddle/optimizer/adam_optimizer.h
+++ b/paddle/optimizer/adam_optimizer.h
@@ -10,6 +10,8 @@ public:
   AdamOptimizer(
       double beta_1, double beta_2, double epsilon, double decay, LrPolicy *lr)
       : ParameterOptimizer(lr),
+        momentums_(nullptr),
+        velocitys_(nullptr),
         beta_1_(beta_1),
         beta_2_(beta_2),
         epsilon_(epsilon),
@@ -20,7 +22,6 @@ public:
   }
   void Update(const Tensor *gradient);
   void set_weight(Tensor *p);
-  real *get_weight() const;
 
 private:
   Tensor *momentums_;
diff --git a/paddle/optimizer/lr_policy.h b/paddle/optimizer/lr_policy.h
index 51debf675f38688384610d860cc46ec4e80b6dea..ab7d1fb0fe6a980df0db52d04bf89f3cfb453147 100644
--- a/paddle/optimizer/lr_policy.h
+++ b/paddle/optimizer/lr_policy.h
@@ -20,7 +20,7 @@ public:
     return learning_rate;
   }
 
-protected:
+private:
   double learning_rate;
 };
 
diff --git a/paddle/optimizer/optimizer.cc b/paddle/optimizer/optimizer.cc
index 5076029494cd55e8e7f7c3f6494c05af432099c6..9572f163ddeaa72105455a1e034f3ae6d0f39d35 100644
--- a/paddle/optimizer/optimizer.cc
+++ b/paddle/optimizer/optimizer.cc
@@ -2,6 +2,7 @@
 #include <string>
 
 #include "parameter_optimizer.h"
+
 using namespace paddle;
 using namespace paddle::optimizer;
 
@@ -26,6 +27,7 @@ MATCH_ENUM_TYPE(int32_t, PADDLE_ELEMENT_TYPE_INT32);
 MATCH_ENUM_TYPE(uint32_t, PADDLE_ELEMENT_TYPE_UINT32);
 MATCH_ENUM_TYPE(int64_t, PADDLE_ELEMENT_TYPE_INT64);
 MATCH_ENUM_TYPE(uint64_t, PADDLE_ELEMENT_TYPE_UINT64);
+// TODO(zhihong): only implement below type, need to fix
 MATCH_ENUM_TYPE(float, PADDLE_ELEMENT_TYPE_FLOAT32);
 MATCH_ENUM_TYPE(double, PADDLE_ELEMENT_TYPE_FLOAT64);
 
@@ -35,15 +37,20 @@ struct paddle_optimizer {
 
 paddle_optimizer* paddle_create_optimizer(const unsigned char* config_proto,
                                           const int config_proto_len,
-                                          const char** state,
-                                          const int state_size) {
+                                          const paddle_element_type data_type,
+                                          void* param_buffer,
+                                          int num_bytes,
+                                          const char* state,
+                                          const int state_len) {
   paddle_optimizer* optimizer = new paddle_optimizer;
   std::string config(config_proto, config_proto + config_proto_len);
   optimizer->impl = ParameterOptimizer::Create(config);
   if (state != nullptr) {
-    std::string s(*state, *state + state_size);
+    std::string s(state, state + state_len);
     optimizer->impl->DeSerializeState(s);
   }
+  Tensor* param = new Tensor(reinterpret_cast<float*>(param_buffer), num_bytes);
+  optimizer->impl->set_weight(param);
   return optimizer;
 }
 
@@ -57,28 +64,19 @@ int paddle_update_parameter(paddle_optimizer* o,
                             const void* grad_buffer,
                             int num_bytes) {
   // TOOD(zhihong): datatype not work. need to add the runtime datatype
-  auto grad_type = reinterpret_cast<const real*>(grad_buffer);
-  Tensor* gradient = new Tensor(const_cast<real*>(grad_type), num_bytes);
+  auto grad_type = reinterpret_cast<const float*>(grad_buffer);
+  Tensor* gradient = new Tensor(const_cast<float*>(grad_type), num_bytes);
   o->impl->Update(gradient);
   return PADDLE_SUCCESS;
 }
 
-int paddle_optimizer_set_weights(paddle_optimizer* o,
-                                 const paddle_element_type data_type,
-                                 void* param_buffer,
-                                 int num_bytes) {
-  // TOOD(zhihong): datatype not work. need to add the runtime datatype
-  Tensor* param = new Tensor(reinterpret_cast<real*>(param_buffer), num_bytes);
-  o->impl->set_weight(param);
-  return PADDLE_SUCCESS;
-}
-
-void* paddle_optimizer_get_weights(paddle_optimizer* o) {
-  void* buffer = (void*)o->impl->get_weight();
-  return buffer;
+int paddle_optimizer_get_weights(paddle_optimizer* o, void** param_buffer) {
+  int param_size = 0;
+  *param_buffer = (void*)o->impl->get_weight(&param_size);
+  return param_size;
 }
 
-int paddle_optimizer_get_state(paddle_optimizer* o, const char* state) {
-  state = o->impl->SerializeState();
-  return PADDLE_SUCCESS;
+int paddle_optimizer_get_state(paddle_optimizer* o, const char** state) {
+  *state = o->impl->SerializeState();
+  return strlen(*state);
 }
diff --git a/paddle/optimizer/optimizer.h b/paddle/optimizer/optimizer.h
index ee017eddabe3b348d96f9ef358b48b7807f38000..a5f468b06b54c8d483ca7c81bac5ea54d4c5d6d4 100644
--- a/paddle/optimizer/optimizer.h
+++ b/paddle/optimizer/optimizer.h
@@ -3,19 +3,18 @@
 #include <stdbool.h>
 #include <stdint.h>
 
-/*! \brief optimizer export C API. which will be used in
-  Case A, on Trainer (On ParameterServer Client) optimize gradient
-
-  Case B, on ParameterServer side optimize gradient
-
-  To simplify the configuration parsing. optimizer *do not* parse any config
-  e.g. learning rate should be calculated by the caller
+/**
+ * @brief optimizer library in independent with other module
+ * which will be used in :
+ * Case A, the gradient optimized locally on the trainer.
+ *
+ * Case B, the gradient optimized on the parameter server.
  */
 
 #ifdef __cplusplus
 extern "C" {
 #endif
-/*! \brief datatypes */
+
 typedef enum {
   PADDLE_ELEMENT_TYPE_INT32 = 0,
   PADDLE_ELEMENT_TYPE_UINT32 = 1,
@@ -25,7 +24,9 @@ typedef enum {
   PADDLE_ELEMENT_TYPE_FLOAT64 = 5,
 } paddle_element_type;
 
-/*! \brief execute status code */
+/**
+ * @brief execution status code
+ */
 const int32_t PADDLE_SUCCESS = 0;
 const int32_t PADDLE_ERROR = -1;
 
@@ -46,8 +47,11 @@ typedef struct paddle_optimizer paddle_optimizer;
  */
 paddle_optimizer* paddle_create_optimizer(const unsigned char* config_proto,
                                           const int config_proto_len,
-                                          const char** state,
-                                          const int state_size);
+                                          const paddle_element_type data_type,
+                                          void* param_buffer,
+                                          int num_bytes,
+                                          const char* state,
+                                          const int state_len);
 
 /**
  *  @brief release optimizer
@@ -72,23 +76,17 @@ int paddle_update_parameter(paddle_optimizer* o,
 
 /**
  *  @brief optimizer instance
- *  @param data_type datatype of gradient
  *  @param param_buffer, initilized parameter buffer
- *  @param num_bytes, parameter size
- *  @return return exec status
+ *  @return return content length
  */
-int paddle_optimizer_set_weights(paddle_optimizer* o,
-                                 const paddle_element_type data_type,
-                                 void* param_buffer,
-                                 int num_bytes);
+int paddle_optimizer_get_weights(paddle_optimizer* o, void** param_buffer);
 
 /**
- *  @brief optimizer instance
- *  @return return content of parameter buffer in optimizer
+ *  @brief optimzizer instance
+ *  @param training state for receive SerializeState
+ *  @return return state_buffer length
  */
-void* paddle_optimizer_get_weights(paddle_optimizer* o);
-
-int paddle_optimizer_get_state(paddle_optimizer* o, const char* state);
+int paddle_optimizer_get_state(paddle_optimizer* o, const char** state);
 
 #ifdef __cplusplus
 }
diff --git a/paddle/optimizer/parameter_optimizer.cc b/paddle/optimizer/parameter_optimizer.cc
index 00e9b858551bbab95a234a9da46fb383b5d50778..1a96880c57464f814d8e64f705cb974eb0e4f682 100644
--- a/paddle/optimizer/parameter_optimizer.cc
+++ b/paddle/optimizer/parameter_optimizer.cc
@@ -24,7 +24,8 @@ ParameterOptimizer *ParameterOptimizer::Create(
                           config.linear_lr().lr_decay_a(),
                           config.linear_lr().lr_decay_b());
     // default
-    return nullptr;
+    LOG(WARNING) << " have not select any LrPolicy. use ConstLr in default";
+    return new ConstLr(0.1);
   };
   LrPolicy *lr = select_lr_policy(config);
   auto select_optimizer =
@@ -36,29 +37,32 @@ ParameterOptimizer *ParameterOptimizer::Create(
                               lr);
     }
     if (config.optimizer() == OptimizerConfig::Adadelta) {
-      return new AdagradOptimizer(
-          config.adagrad().epsilon(), config.adagrad().decay(), lr);
+      return new AdadeltaOptimizer(config.adadelta().rho(),
+                                   config.adadelta().epsilon(),
+                                   config.adadelta().decay(),
+                                   lr);
     }
     if (config.optimizer() == OptimizerConfig::Adagrad) {
       return new AdagradOptimizer(
           config.adagrad().epsilon(), config.adagrad().decay(), lr);
     }
     if (config.optimizer() == OptimizerConfig::Adam) {
-      return new AdadeltaOptimizer(config.adadelta().rho(),
-                                   config.adadelta().epsilon(),
-                                   config.adadelta().decay(),
-                                   lr);
+      return new AdamOptimizer(config.adam().beta_1(),
+                               config.adam().beta_2(),
+                               config.adam().epsilon(),
+                               config.adam().decay(),
+                               lr);
     }
     // default
-    return new SGDOptimizer(config.sgd().momentum(),
-                            config.sgd().decay(),
-                            config.sgd().nesterov(),
-                            lr);
+    LOG(WARNING)
+        << "have not select any Optimizer. use SGDOptimizer in default";
+    return new SGDOptimizer(0.0, 0.0, false, lr);
   };
   return select_optimizer(config);
 }
 
-real *ParameterOptimizer::get_weight() const {
+float *ParameterOptimizer::get_weight(int *param_size) const {
+  *param_size = (int)parameter_->size();
   return parameter_->get_buffer();
 }
 
diff --git a/paddle/optimizer/parameter_optimizer.h b/paddle/optimizer/parameter_optimizer.h
index 33b3f837b43c2af3fc4372dc6d47b0aaf1894814..f65f1d71a4271b2317d3e5714435cd2e68f3a54c 100644
--- a/paddle/optimizer/parameter_optimizer.h
+++ b/paddle/optimizer/parameter_optimizer.h
@@ -25,11 +25,10 @@ public:
   virtual const char *SerializeState();
   virtual void DeSerializeState(const std::string &state);
   virtual void Update(const Tensor *gradient) = 0;
-  virtual real *get_weight() const;
+  virtual float *get_weight(int *param_size) const;
   virtual void set_weight(Tensor *parameter);
 
 protected:
-  OptimizerConfig config_;
   Tensor *parameter_;
 
   // learning rate policy
diff --git a/paddle/optimizer/parameter_optimizer_test.cpp b/paddle/optimizer/parameter_optimizer_test.cpp
index d9f2ed8e950fb7f9aff0638f75c094909ca5e329..d39d50a1abf4651650252ef55440959d71a1c5ac 100644
--- a/paddle/optimizer/parameter_optimizer_test.cpp
+++ b/paddle/optimizer/parameter_optimizer_test.cpp
@@ -77,7 +77,8 @@ public:
       opts[i]->set_weight(p);
     }
     for (size_t i = 0; i < opts.size(); ++i) {
-      real* newp = (real*)opts[i]->get_weight();
+      int s = 0;
+      float* newp = (float*)opts[i]->get_weight(&s);
       for (size_t j = 0; j < size; ++j) {
         EXPECT_EQ(newp[j], (*p)[j]);
       }
diff --git a/paddle/optimizer/sgd_optimizer.h b/paddle/optimizer/sgd_optimizer.h
index 284d0a4d0c7ea7cb627f810b3e8044f3aeabb0c4..1bb97349c7cdcf7a7604d9f10a9aa3eb91f47971 100644
--- a/paddle/optimizer/sgd_optimizer.h
+++ b/paddle/optimizer/sgd_optimizer.h
@@ -9,14 +9,18 @@ namespace optimizer {
 class SGDOptimizer : public ParameterOptimizer {
 public:
   SGDOptimizer(double m, double d, bool n, LrPolicy* lr)
-      : ParameterOptimizer(lr), momentum_(m), decay_(d), nesterov_(n) {}
+      : ParameterOptimizer(lr),
+        momentums_(nullptr),
+        momentum_(m),
+        decay_(d),
+        nesterov_(n) {}
   virtual ~SGDOptimizer() { delete momentums_; }
   void Update(const Tensor* gradient);
   const char* SerializeState();
   void DeSerializeState(const std::string& state);
 
   void set_weight(Tensor* p);
-  real* get_weight() const;
+  float* get_weight(int* param_size) const;
 
 private:
   Tensor* momentums_;
diff --git a/paddle/optimizer/sgd_optmizer.cc b/paddle/optimizer/sgd_optmizer.cc
index b40bf7c1020b0567808be395cd2c3e23810a621c..fea550f8d1d7c4c0051a12e880ce815c9e74ef43 100644
--- a/paddle/optimizer/sgd_optmizer.cc
+++ b/paddle/optimizer/sgd_optmizer.cc
@@ -16,7 +16,7 @@ void SGDOptimizer::set_weight(Tensor *p) {
 void SGDOptimizer::Update(const Tensor *gradient) {
   num_sample_passed_ += 1;
   double learning_rate = lr_policy_->LearningRate(num_sample_passed_);
-  real velocity = 0.0;
+  float velocity = 0.0;
   Tensor &param = *parameter_;
   const Tensor &grad = *gradient;
   Tensor &m = *momentums_;