diff --git a/python/paddle/v2/fluid/layers/nn.py b/python/paddle/v2/fluid/layers/nn.py
index 051b5368180d3f7951b100c26fb7367372d9a343..fcb55c8d4da5584a01e48757a335a418db9375fa 100644
--- a/python/paddle/v2/fluid/layers/nn.py
+++ b/python/paddle/v2/fluid/layers/nn.py
@@ -831,12 +831,12 @@ def crf_decoding(input, param_attr, label=None):
     return viterbi_path
 
 
-def cos_sim(X, Y, **kwargs):
+def cos_sim(X, Y):
     """
     This function performs the cosine similarity between two tensors
     X and Y and returns that as the output.
     """
-    helper = LayerHelper('cos_sim', **kwargs)
+    helper = LayerHelper('cos_sim', **locals())
     out = helper.create_tmp_variable(dtype=X.dtype)
     xnorm = helper.create_tmp_variable(dtype=X.dtype)
     ynorm = helper.create_tmp_variable(dtype=X.dtype)
@@ -850,7 +850,7 @@ def cos_sim(X, Y, **kwargs):
     return out
 
 
-def dropout(x, dropout_prob, is_test=False, seed=None, **kwargs):
+def dropout(x, dropout_prob, is_test=False, seed=None):
     """
     Computes dropout.
 
@@ -879,7 +879,7 @@ def dropout(x, dropout_prob, is_test=False, seed=None, **kwargs):
           droped = fluid.layers.dropout(input=x, dropout_rate=0.5)
     """
 
-    helper = LayerHelper('dropout', **kwargs)
+    helper = LayerHelper('dropout', **locals())
     out = helper.create_tmp_variable(dtype=x.dtype)
     mask = helper.create_tmp_variable(dtype=x.dtype, stop_gradient=True)
     helper.append_op(
@@ -896,7 +896,7 @@ def dropout(x, dropout_prob, is_test=False, seed=None, **kwargs):
     return out
 
 
-def cross_entropy(input, label, **kwargs):
+def cross_entropy(input, label, soft_label=False):
     """
     **Cross Entropy Layer**
 
@@ -905,15 +905,15 @@ def cross_entropy(input, label, **kwargs):
     computation.
 
     1) One-hot cross-entropy:
-	`soft_label = False`, `Label[i, 0]` indicates the class index for sample i:
+        `soft_label = False`, `Label[i, 0]` indicates the class index for sample i:
 
         .. math::
 
             Y[i] = -\log(X[i, Label[i]])
 
     2) Soft-label cross-entropy:
-	`soft_label = True`, `Label[i, j]` indicates the soft label of class j
-	for sample i:
+        `soft_label = True`, `Label[i, j]` indicates the soft label of class j
+        for sample i:
 
         .. math::
 
@@ -923,8 +923,8 @@ def cross_entropy(input, label, **kwargs):
        equals one.
 
     3) One-hot cross-entropy with vecterized `label`:
-	 As a special case of 2), when each row of 'label' has only one
-	 non-zero element which is equal to 1, soft-label cross-entropy degenerates
+         As a special case of 2), when each row of 'label' has only one
+         non-zero element which is equal to 1, soft-label cross-entropy degenerates
          to a one-hot cross-entropy with one-hot label representation.
 
     Args:
@@ -938,7 +938,7 @@ def cross_entropy(input, label, **kwargs):
                                tensor<int64> with shape [N x 1]. When
                                `soft_label` is set to `True`, `label` is a
                                tensor<float/double> with shape [N x D].
-        soft_label (bool, via `**kwargs`): a flag indicating whether to
+        soft_label (bool): a flag indicating whether to
                                            interpretate the given labels as soft
                                            labels, default `False`.
 
@@ -958,18 +958,18 @@ def cross_entropy(input, label, **kwargs):
           predict = fluid.layers.fc(input=net, size=classdim, act='softmax')
           cost = fluid.layers.cross_entropy(input=predict, label=label)
     """
-    helper = LayerHelper('cross_entropy', **kwargs)
+    helper = LayerHelper('cross_entropy', **locals())
     out = helper.create_tmp_variable(dtype=input.dtype)
     helper.append_op(
         type='cross_entropy',
         inputs={'X': [input],
                 'Label': [label]},
         outputs={'Y': [out]},
-        attrs=kwargs)
+        attrs={"soft_label": soft_label})
     return out
 
 
-def square_error_cost(input, label, **kwargs):
+def square_error_cost(input, label):
     """
     **Square error cost layer**
 
@@ -1004,7 +1004,7 @@ def square_error_cost(input, label, **kwargs):
           cost = layers.square_error_cost(input=y_predict, label=y)
 
     """
-    helper = LayerHelper('square_error_cost', **kwargs)
+    helper = LayerHelper('square_error_cost', **locals())
     minus_out = helper.create_tmp_variable(dtype=input.dtype)
     helper.append_op(
         type='elementwise_sub',
@@ -1019,12 +1019,12 @@ def square_error_cost(input, label, **kwargs):
     return square_out
 
 
-def accuracy(input, label, k=1, correct=None, total=None, **kwargs):
+def accuracy(input, label, k=1, correct=None, total=None):
     """
     This function computes the accuracy using the input and label.
     The output is the top_k inputs and their indices.
     """
-    helper = LayerHelper("accuracy", **kwargs)
+    helper = LayerHelper("accuracy", **locals())
     topk_out = helper.create_tmp_variable(dtype=input.dtype)
     topk_indices = helper.create_tmp_variable(dtype="int64")
     helper.append_op(
@@ -1057,13 +1057,12 @@ def chunk_eval(input,
                label,
                chunk_scheme,
                num_chunk_types,
-               excluded_chunk_types=None,
-               **kwargs):
+               excluded_chunk_types=None):
     """
     This function computes and outputs the precision, recall and
     F1-score of chunk detection.
     """
-    helper = LayerHelper("chunk_eval", **kwargs)
+    helper = LayerHelper("chunk_eval", **locals())
 
     # prepare output
     precision = helper.create_tmp_variable(dtype="float32")
@@ -1295,7 +1294,7 @@ def conv2d(input,
     return helper.append_activation(pre_act)
 
 
-def sequence_pool(input, pool_type, **kwargs):
+def sequence_pool(input, pool_type):
     """
     This function add the operator for sequence pooling.
     It pools features of all time-steps of each instance, and is applied
@@ -1345,7 +1344,7 @@ def sequence_pool(input, pool_type, **kwargs):
              sqrt_x = fluid.layers.sequence_pool(input=x, pool_type='sqrt')
              max_x = fluid.layers.sequence_pool(input=x, pool_type='max')
     """
-    helper = LayerHelper('sequence_pool', input=input, **kwargs)
+    helper = LayerHelper('sequence_pool', **locals())
     dtype = helper.input_dtype()
     pool_out = helper.create_tmp_variable(dtype)
     max_index = helper.create_tmp_variable(dtype)
@@ -1365,7 +1364,7 @@ def sequence_pool(input, pool_type, **kwargs):
     return pool_out
 
 
-def sequence_first_step(input, **kwargs):
+def sequence_first_step(input):
     """
     This funciton get the first step of sequence.
 
@@ -1398,7 +1397,7 @@ def sequence_first_step(input, **kwargs):
     return sequence_pool(input=input, pool_type="first")
 
 
-def sequence_last_step(input, **kwargs):
+def sequence_last_step(input):
     """
     This funciton get the last step of sequence.
 
@@ -2338,7 +2337,8 @@ def l2_normalize(x, axis, epsilon=1e-12, name=None):
           normed = fluid.layers.l2_normalize(x=data, axis=1)
     """
 
-    if len(x.shape) == 1: axis = 0
+    if len(x.shape) == 1:
+        axis = 0
 
     helper = LayerHelper("l2_normalize", **locals())
 
@@ -2656,7 +2656,7 @@ def ctc_greedy_decoder(input, blank, name=None):
     return ctc_out
 
 
-def warpctc(input, label, blank=0, norm_by_times=False, **kwargs):
+def warpctc(input, label, blank=0, norm_by_times=False):
     """
     An operator integrating the open source Warp-CTC library
     (https://github.com/baidu-research/warp-ctc)
@@ -2697,7 +2697,7 @@ def warpctc(input, label, blank=0, norm_by_times=False, **kwargs):
             cost = layers.warpctc(input=y_predict, label=y)
 
     """
-    helper = LayerHelper('warpctc', **kwargs)
+    helper = LayerHelper('warpctc', **locals())
     loss_out = helper.create_tmp_variable(dtype=input.dtype)
     grad_out = helper.create_tmp_variable(dtype=input.dtype)
     helper.append_op(