diff --git a/paddle/pybind/protobuf.cc b/paddle/pybind/protobuf.cc
index 126c2ce1c7d0efe640b8095b4861c3a96cff42c2..de6db60730b2434379711deb52721ed826246af7 100644
--- a/paddle/pybind/protobuf.cc
+++ b/paddle/pybind/protobuf.cc
@@ -50,12 +50,12 @@ public:
 
   VarDesc *Proto() { return &desc_; }
 
-  void SetShape(const vector<int64_t> &dims) {
+  void SetShape(const std::vector<int64_t> &dims) {
     VectorToRepeated(dims, desc_.mutable_lod_tensor()->mutable_dims());
   }
 
   void SetDataType(int type_id) {
-    desc_.mutable_lod_tensor()->set_data_type(const_cast<DataType>(type_id));
+    desc_.mutable_lod_tensor()->set_data_type(static_cast<DataType>(type_id));
   }
 
   std::vector<int64_t> Shape() {
@@ -86,7 +86,8 @@ public:
 
   int32_t Parent() const { return desc_->parent_idx(); }
 
-  VarDescBind *NewVar(const std::string &name) {
+  VarDescBind *NewVar(py::bytes name_bytes) {
+    std::string name = name_bytes;
     need_update_ = true;
     auto it = vars_.find(name);
     PADDLE_ENFORCE(it == vars_.end(), "Duplicated variable %s", name);
@@ -224,16 +225,15 @@ void BindBlockDesc(py::module &m) {
            &BlockDescBind::AppendOp,
            py::return_value_policy::reference)
       .def("new_var",
-           [](BlockDesc &self) { return self.add_vars(); },
+           &BlockDescBind::NewVar,
            py::return_value_policy::reference);
 }
 
 void BindVarDsec(py::module &m) {
-  py::class_<VarDesc>(m, "VarDesc", "")
-      .def(py::init<>())
-      .def("set_shape", VarDescBind::SetShape)
-      .def("set_data_type", VarDescBind::SetDataType)
-      .def("shape", VarDescBind::Shape);
+  py::class_<VarDescBind>(m, "VarDesc", "")
+      .def("set_shape", &VarDescBind::SetShape)
+      .def("set_data_type", &VarDescBind::SetDataType)
+      .def("shape", &VarDescBind::Shape);
 }
 
 void BindOpDesc(py::module &m) {
diff --git a/python/paddle/v2/framework/tests/test_protobuf_descs.py b/python/paddle/v2/framework/tests/test_protobuf_descs.py
index fbe1f7152bb12dd7ddc69894a9ce2a892784d8f0..f1074f6bb5054edd2a1a9f0b1846aaff70917965 100644
--- a/python/paddle/v2/framework/tests/test_protobuf_descs.py
+++ b/python/paddle/v2/framework/tests/test_protobuf_descs.py
@@ -33,7 +33,7 @@ class TestVarDesc(unittest.TestCase):
     def test_shape(self):
         program_desc = core.ProgramDesc.instance()
         block = program_desc.root_block()
-        var = block.new_var()
+        var = block.new_var('my_var')
         src_shape = [3, 2, 10, 8]
         var.set_shape(src_shape)
         res_shape = var.shape()