diff --git a/doc/design/python_api.md b/doc/design/python_api.md
index 6213da65c8c5931bc16e42574b8628b676424873..c4665e44fca6e75878d76ba0a686f87f10222988 100644
--- a/doc/design/python_api.md
+++ b/doc/design/python_api.md
@@ -22,7 +22,7 @@ Whenever we create a block, we need to set its parent block to the current block
 ```python
 class Program(objects):
     def __init__(self):
-        self.proto = core.NewProgram() # a C++ ProgramDesc pointer.
+        self.desc = core.NewProgram() # a C++ ProgramDesc pointer.
         self.blocks = vector<Block>()
         self.blocks.append(Block(self, -1)) # the global block
         self.current_block = 0          # initialized to the global block
@@ -57,7 +57,7 @@ A [Block](https://github.com/PaddlePaddle/Paddle/blob/develop/doc/design/block.m
 ```python
 class Block(objects):
     def __init__(self, program, parent_idx):
-        self.proto = core.NewBlock(program.proto)
+        self.desc = core.NewBlock(program.desc)
         self.program = program
         self.vars = map<string, Variable>()
         self.ops = vector<Operator>()
@@ -98,11 +98,11 @@ class Operator(object):
                  outputs,# dict<stirng, Variable>
                  attrs   # dict<string, Any>
                  ):
-        self.proto = core.NewOpDesc(block.proto, type, inputs, outputs, attrs)
-        core.infer_shape(self.proto, inputs, outputs)
+        self.desc = core.NewOpDesc(block.desc, type, inputs, outputs, attrs)
+        core.infer_shape(self.desc, inputs, outputs)
 
     def type(self):
-        return self.proto.type()
+        return self.desc.type()
 ```
 
 `Operator` creates the `OpDesc` message in C++ space, so that it can call the `InferShape` function, which is in C++.
@@ -124,7 +124,7 @@ class Variable(object):
             name = unique_name_generator()
         self.name = name
         self.block = block
-        self.proto = core.NewVarDesc(block.proto, name, shape, lod_level)
+        self.desc = core.NewVarDesc(block.desc, name, shape, lod_level)
         self.writer = None
 ```
 
diff --git a/python/paddle/v2/framework/graph.py b/python/paddle/v2/framework/graph.py
index 6f2a76a9835696430ef9a23630736c5d151d8db2..7fb72c36381e95c871a298d2088d1cc6cd39bcfc 100644
--- a/python/paddle/v2/framework/graph.py
+++ b/python/paddle/v2/framework/graph.py
@@ -11,18 +11,18 @@ class Variable(object):
 
         if name is None:
             name = Variable._unique_var_name_()
-        self.proto = self.block.proto.new_var(name)
+        self.desc = self.block.desc.new_var(name)
 
         if shape is not None:
-            self.proto.set_shape(shape)
+            self.desc.set_shape(shape)
 
         if dtype is not None:
             # TODO(yuyang18): Convert dtype from numpy.dtype
-            self.proto.set_data_type(dtype)
+            self.desc.set_data_type(dtype)
 
         if lod_level is not None:
             # TODO(yuyang18): set_lod_level is not defined.
-            self.proto.set_lod_level(lod_level)
+            self.desc.set_lod_level(lod_level)
 
         self.block.vars[name] = self
         self.op = None
@@ -38,13 +38,13 @@ class Variable(object):
 class Operator(object):
     def __init__(self,
                  block,
-                 proto,
+                 desc,
                  type=None,
                  inputs=None,
                  outputs=None,
                  attrs=None):
         self.block = block
-        self.proto = proto
+        self.desc = desc
         if type is not None:
             # TODO.
             pass
@@ -63,31 +63,31 @@ class Operator(object):
 
 class Block(object):
     def __init__(self, program, idx):
-        self.proto = program.proto.block(idx)
+        self.desc = program.desc.block(idx)
         self.vars = dict()  # var_name --> var
         self.ops = collections.deque()  # operator list
         self.program = program
 
     @property
     def parent_idx(self):
-        return self.proto.parent
+        return self.desc.parent
 
     @property
     def idx(self):
-        return self.proto.id
+        return self.desc.id
 
     def create_var(self, *args, **kwargs):
         return Variable(self, *args, **kwargs)
 
     def append_op(self, *args, **kwargs):
-        op_proto = self.proto.append_op()
-        op = Operator(self, op_proto, *args, **kwargs)
+        op_desc = self.desc.append_op()
+        op = Operator(self, op_desc, *args, **kwargs)
         self.ops.append(op)
         return op
 
     def prepend_op(self, *args, **kwargs):
-        op_proto = self.proto.prepend_op()
-        op = Operator(self, op_proto, *args, **kwargs)
+        op_desc = self.desc.prepend_op()
+        op = Operator(self, op_desc, *args, **kwargs)
         self.ops.appendleft(op)
         return op
 
@@ -104,7 +104,7 @@ class Program(object):
     def __init__(self):
         assert not hasattr(self.__class__,
                            '_instance'), 'Do not call constructor directly!'
-        self.proto = core.ProgramDesc.instance()
+        self.desc = core.ProgramDesc.instance()
         self.blocks = [Block(self, 0)]
         self.current_block_idx = 0
 
@@ -116,7 +116,7 @@ class Program(object):
 
     def create_block(self):
         new_block_idx = len(self.blocks)
-        self.proto.append_block(self.current_block().proto)
+        self.desc.append_block(self.current_block().desc)
         self.current_block_idx = new_block_idx
         self.blocks.append(Block(self, self.current_block_idx))
         return self.current_block()