diff --git a/dygraph/ocr_recognition/train.py b/dygraph/ocr_recognition/train.py
index f333d3e293293f29b9e639c86415fa1fd824c786..234969e967072c682320ce41c50db113eaab89c4 100644
--- a/dygraph/ocr_recognition/train.py
+++ b/dygraph/ocr_recognition/train.py
@@ -331,9 +331,6 @@ class SimpleAttention(fluid.dygraph.Layer):
                        act=None,
                        bias_attr=False)
 
-    def _build_once(self, encoder_vec, encoder_proj, decoder_state):
-        pass
-
     def forward(self, encoder_vec, encoder_proj, decoder_state):
 
         decoder_state_fc = self.fc_1(decoder_state)
@@ -381,9 +378,6 @@ class GRUDecoderWithAttention(fluid.dygraph.Layer):
 
         self.decoder_size = decoder_size
 
-    def _build_once(self, target_embedding, encoder_vec, encoder_proj,
-                    decoder_boot):
-        pass
 
     def forward(self, target_embedding, encoder_vec, encoder_proj,
                 decoder_boot):
@@ -431,8 +425,6 @@ class OCRAttention(fluid.dygraph.Layer):
         self.gru_decoder_with_attention = GRUDecoderWithAttention(
             self.full_name(), Config.decoder_size, Config.num_classes)
 
-    def _build_once(self, inputs, label_in):
-        pass
 
     def forward(self, inputs, label_in):
         gru_backward, encoded_vector, encoded_proj = self.encoder_net(inputs)
diff --git a/dygraph/pbt_lm/ptb_dy.py b/dygraph/pbt_lm/ptb_dy.py
index 11df408fdf106a79ccd5702f280c176da919dba4..f93a80085be5704d3ed970f05475c136005e73de 100644
--- a/dygraph/pbt_lm/ptb_dy.py
+++ b/dygraph/pbt_lm/ptb_dy.py
@@ -56,7 +56,6 @@ class SimpleLSTMRNN(fluid.Layer):
         self.cell_array = []
         self.hidden_array = []
 
-        #build_once()
         self.weight_1_arr = []
         self.weight_2_arr = []
         self.bias_arr = []
@@ -81,35 +80,6 @@ class SimpleLSTMRNN(fluid.Layer):
                 default_initializer=fluid.initializer.Constant(0.0))
             self.bias_arr.append(self.add_parameter('b_%d' % i, bias_1))
 
-    def build_once(self, input_embedding, init_hidden=None, init_cell=None):
-
-        pass
-        '''
-        self.weight_1_arr = []
-        self.weight_2_arr = []
-        self.bias_arr = []
-        self.mask_array = []
-
-        for i in range(self._num_layers):
-            weight_1 = self.create_parameter(
-                attr=fluid.ParamAttr(
-                    initializer=fluid.initializer.UniformInitializer(
-                        low=-self._init_scale, high=self._init_scale)),
-                shape=[self._hidden_size * 2, self._hidden_size * 4],
-                dtype="float32",
-                default_initializer=fluid.initializer.UniformInitializer(
-                    low=-self._init_scale, high=self._init_scale))
-            self.weight_1_arr.append(self.add_parameter('w_%d' % i, weight_1))
-            bias_1 = self.create_parameter(
-                attr=fluid.ParamAttr(
-                    initializer=fluid.initializer.UniformInitializer(
-                        low=-self._init_scale, high=self._init_scale)),
-                shape=[self._hidden_size * 4],
-                dtype="float32",
-                default_initializer=fluid.initializer.Constant(0.0))
-            self.bias_arr.append(self.add_parameter('b_%d' % i, bias_1))
-        '''
-
     def forward(self, input_embedding, init_hidden=None, init_cell=None):
         self.cell_array = []
         self.hidden_array = []