diff --git a/paddleslim/core/__init__.py b/paddleslim/core/__init__.py
index f6ad753dfa11c695be32a2211e27dddfdaed7072..9bb4b2bf34f3aed2f74ce4fd5936527b17737181 100644
--- a/paddleslim/core/__init__.py
+++ b/paddleslim/core/__init__.py
@@ -14,4 +14,8 @@
 
 from . import graph_wrapper
 from .graph_wrapper import *
+from . import registry
+from .registry import *
+
 __all__ = graph_wrapper.__all__
+__all__ += registry.__all__
diff --git a/paddleslim/nas/utils/registry.py b/paddleslim/core/registry.py
similarity index 51%
rename from paddleslim/nas/utils/registry.py
rename to paddleslim/core/registry.py
index 5d055a9c3de98db19bc2f6ccd85f762b384e6ce3..208dceca1ff9958591b7e427d47124f3c57e4d5b 100644
--- a/paddleslim/nas/utils/registry.py
+++ b/paddleslim/core/registry.py
@@ -1,16 +1,36 @@
+# Copyright (c) 2019  PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
 import inspect
 
+__all__ = ["Registry"]
+
+
 class Registry(object):
     def __init__(self, name):
         self._name = name
         self._module_dict = dict()
+
     def __repr__(self):
-        format_str = self.__class__.__name__ + '(name={}, items={})'.format(self._name, list(self._module_dict.keys()))
+        format_str = self.__class__.__name__ + '(name={}, items={})'.format(
+            self._name, list(self._module_dict.keys()))
         return format_str
 
     @property
     def name(self):
         return self._name
+
     @property
     def module_dict(self):
         return self._module_dict
@@ -20,12 +40,14 @@ class Registry(object):
 
     def _register_module(self, module_class):
         if not inspect.isclass(module_class):
-            raise TypeError('module must be a class, but receive {}.'.format(type(module_class)))
+            raise TypeError('module must be a class, but receive {}.'.format(
+                type(module_class)))
         module_name = module_class.__name__
         if module_name in self._module_dict:
-            raise KeyError('{} is already registered in {}.'.format(module_name, self.name))
+            raise KeyError('{} is already registered in {}.'.format(
+                module_name, self.name))
         self._module_dict[module_name] = module_class
 
-    def register_module(self, cls):
+    def register(self, cls):
         self._register_module(cls)
         return cls
diff --git a/paddleslim/nas/__init__.py b/paddleslim/nas/__init__.py
index 9d0531501ca43921438ee5b2fb58ac0ad2396d1b..2f5509144f53529ae717b72bbb7252b4b06a0048 100644
--- a/paddleslim/nas/__init__.py
+++ b/paddleslim/nas/__init__.py
@@ -11,3 +11,9 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
+import search_space
+from search_space import *
+
+__all__ = []
+__all__ += search_space.__all__
diff --git a/paddleslim/nas/utils/__init__.py b/paddleslim/nas/search_space/__init__.py
similarity index 61%
rename from paddleslim/nas/utils/__init__.py
rename to paddleslim/nas/search_space/__init__.py
index 9d0531501ca43921438ee5b2fb58ac0ad2396d1b..767760fabca2803d2cd9c6ec4a51ec2562fcfb5c 100644
--- a/paddleslim/nas/utils/__init__.py
+++ b/paddleslim/nas/search_space/__init__.py
@@ -11,3 +11,16 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
+from .mobilenetv2_space import MobileNetV2Space
+import search_space_registry
+from search_space_registry import *
+import search_space_factory
+from search_space_factory import *
+import search_space_base
+from search_space_base import *
+
+__all__ = ["MobileNetV2Space"]
+__all__ += search_space_registry.__all__
+__all__ += search_space_factory.__all__
+__all__ += search_space_base.__all__
diff --git a/paddleslim/nas/searchspace/base_layer.py b/paddleslim/nas/search_space/base_layer.py
similarity index 59%
rename from paddleslim/nas/searchspace/base_layer.py
rename to paddleslim/nas/search_space/base_layer.py
index 75ce180b4279e32601fe3fab6fea44d719a1a701..431e025ed824c7c78ac1e38ad27a785315b0fef4 100644
--- a/paddleslim/nas/searchspace/base_layer.py
+++ b/paddleslim/nas/search_space/base_layer.py
@@ -16,7 +16,15 @@ import paddle.fluid as fluid
 from paddle.fluid.param_attr import ParamAttr
 
 
-def conv_bn_layer(input, filter_size, num_filters, stride, padding, num_groups=1, act=None, name=None, use_cudnn=True):
+def conv_bn_layer(input,
+                  filter_size,
+                  num_filters,
+                  stride,
+                  padding,
+                  num_groups=1,
+                  act=None,
+                  name=None,
+                  use_cudnn=True):
     """Build convolution and batch normalization layers.
     Args:
         input(Variable): input.
@@ -31,11 +39,24 @@ def conv_bn_layer(input, filter_size, num_filters, stride, padding, num_groups=1
     Returns:
         Variable, layers output.
     """
-    conv = fluid.layers.conv2d(input, num_filters=num_filters, filter_size=filter_size, stride=stride, padding=padding, 
-                               groups=num_groups, act=None, use_cudnn=use_cudnn, param_attr=ParamAttr(name=name+'_weights'), bias_attr=False)
+    conv = fluid.layers.conv2d(
+        input,
+        num_filters=num_filters,
+        filter_size=filter_size,
+        stride=stride,
+        padding=padding,
+        groups=num_groups,
+        act=None,
+        use_cudnn=use_cudnn,
+        param_attr=ParamAttr(name=name + '_weights'),
+        bias_attr=False)
     bn_name = name + '_bn'
-    bn = fluid.layers.batch_norm(input=conv, param_attr=ParamAttr(name=bn_name+'_scale'), bias_attr=ParamAttr(name=bn_name+'_offset'),
-                                 moving_mean_name=bn_name+'_mean', moving_variance_name=bn_name+'_variance')
+    bn = fluid.layers.batch_norm(
+        input=conv,
+        param_attr=ParamAttr(name=bn_name + '_scale'),
+        bias_attr=ParamAttr(name=bn_name + '_offset'),
+        moving_mean_name=bn_name + '_mean',
+        moving_variance_name=bn_name + '_variance')
     if act == 'relu6':
         return fluid.layers.relu6(bn)
     else:
diff --git a/paddleslim/nas/searchspace/mobilenetv2_space.py b/paddleslim/nas/search_space/mobilenetv2_space.py
similarity index 73%
rename from paddleslim/nas/searchspace/mobilenetv2_space.py
rename to paddleslim/nas/search_space/mobilenetv2_space.py
index e09e00a6d8d685dff6e0e373ad97629b48dafd2a..0455fc9521bf5881cb6ad7eedeb97276a01b39bb 100644
--- a/paddleslim/nas/searchspace/mobilenetv2_space.py
+++ b/paddleslim/nas/search_space/mobilenetv2_space.py
@@ -17,30 +17,39 @@ from __future__ import division
 from __future__ import print_function
 
 import sys
-sys.path.append('..')
 import numpy as np
 import paddle.fluid as fluid
 from paddle.fluid.param_attr import ParamAttr
-from searchspacebase import SearchSpaceBase
+from .search_space_base import SearchSpaceBase
 from .base_layer import conv_bn_layer
-from .registry import SEARCHSPACE
+from .search_space_registry import SEARCHSPACE
 
-@SEARCHSPACE.register_module
+
+@SEARCHSPACE.register
 class MobileNetV2Space(SearchSpaceBase):
-    def __init__(self, input_size, output_size, block_num, scale=1.0, class_dim=1000):
-        super(MobileNetV2Space, self).__init__(input_size, output_size, block_num)
-        self.head_num = np.array([3,4,8,12,16,24,32]) #7
-        self.filter_num1 = np.array([3,4,8,12,16,24,32,48]) #8
-        self.filter_num2 = np.array([8,12,16,24,32,48,64,80]) #8
-        self.filter_num3 = np.array([16,24,32,48,64,80,96,128]) #8
-        self.filter_num4 = np.array([24,32,48,64,80,96,128,144,160,192]) #10
-        self.filter_num5 = np.array([32,48,64,80,96,128,144,160,192,224]) #10
-        self.filter_num6 = np.array([64,80,96,128,144,160,192,224,256,320,384,512]) #12
-        self.k_size = np.array([3,5]) #2
-        self.multiply = np.array([1,2,3,4,6]) #5
-        self.repeat = np.array([1,2,3,4,5,6]) #6
-        self.scale=scale
-        self.class_dim=class_dim
+    def __init__(self,
+                 input_size,
+                 output_size,
+                 block_num,
+                 scale=1.0,
+                 class_dim=1000):
+        super(MobileNetV2Space, self).__init__(input_size, output_size,
+                                               block_num)
+        self.head_num = np.array([3, 4, 8, 12, 16, 24, 32])  #7
+        self.filter_num1 = np.array([3, 4, 8, 12, 16, 24, 32, 48])  #8
+        self.filter_num2 = np.array([8, 12, 16, 24, 32, 48, 64, 80])  #8
+        self.filter_num3 = np.array([16, 24, 32, 48, 64, 80, 96, 128])  #8
+        self.filter_num4 = np.array(
+            [24, 32, 48, 64, 80, 96, 128, 144, 160, 192])  #10
+        self.filter_num5 = np.array(
+            [32, 48, 64, 80, 96, 128, 144, 160, 192, 224])  #10
+        self.filter_num6 = np.array(
+            [64, 80, 96, 128, 144, 160, 192, 224, 256, 320, 384, 512])  #12
+        self.k_size = np.array([3, 5])  #2
+        self.multiply = np.array([1, 2, 3, 4, 6])  #5
+        self.repeat = np.array([1, 2, 3, 4, 5, 6])  #6
+        self.scale = scale
+        self.class_dim = class_dim
 
     def init_tokens(self):
         """
@@ -49,28 +58,47 @@ class MobileNetV2Space(SearchSpaceBase):
         each line in the following represent the index of the [expansion_factor, filter_num, repeat_num, kernel_size]
         """
         # original MobileNetV2
-        return [4,          # 1, 16, 1
-                4, 5, 1, 0, # 6, 24, 1
-                4, 5, 1, 0, # 6, 24, 2
-                4, 4, 2, 0, # 6, 32, 3
-                4, 4, 3, 0, # 6, 64, 4
-                4, 5, 2, 0, # 6, 96, 3
-                4, 7, 2, 0, # 6, 160, 3
-                4, 9, 0, 0] # 6, 320, 1
+        return [
+            4,  # 1, 16, 1
+            4,
+            5,
+            1,
+            0,  # 6, 24, 1
+            4,
+            5,
+            1,
+            0,  # 6, 24, 2
+            4,
+            4,
+            2,
+            0,  # 6, 32, 3
+            4,
+            4,
+            3,
+            0,  # 6, 64, 4
+            4,
+            5,
+            2,
+            0,  # 6, 96, 3
+            4,
+            7,
+            2,
+            0,  # 6, 160, 3
+            4,
+            9,
+            0,
+            0
+        ]  # 6, 320, 1
 
     def range_table(self):
         """
         get range table of current search space 
         """
         # head_num + 7 * [multiple(expansion_factor), filter_num, repeat, kernel_size]
-        return [7, 
-                5, 8, 6, 2,
-                5, 8, 6, 2,
-                5, 8, 6, 2,
-                5, 8, 6, 2,
-                5, 10, 6, 2,
-                5, 10, 6, 2,
-                5, 12, 6, 2]
+        return [
+            7, 5, 8, 6, 2, 5, 8, 6, 2, 5, 8, 6, 2, 5, 8, 6, 2, 5, 10, 6, 2, 5,
+            10, 6, 2, 5, 12, 6, 2
+        ]
 
     def token2arch(self, tokens=None):
         """
@@ -81,16 +109,24 @@ class MobileNetV2Space(SearchSpaceBase):
 
         base_bottleneck_params_list = [
             (1, self.head_num[tokens[0]], 1, 1, 3),
-            (self.multiply[tokens[1]], self.filter_num1[tokens[2]], self.repeat[tokens[3]], 2, self.k_size[tokens[4]]),
-            (self.multiply[tokens[5]], self.filter_num1[tokens[6]], self.repeat[tokens[7]], 2, self.k_size[tokens[8]]),
-            (self.multiply[tokens[9]], self.filter_num2[tokens[10]], self.repeat[tokens[11]], 2, self.k_size[tokens[12]]),
-            (self.multiply[tokens[13]], self.filter_num3[tokens[14]], self.repeat[tokens[15]], 2, self.k_size[tokens[16]]),
-            (self.multiply[tokens[17]], self.filter_num3[tokens[18]], self.repeat[tokens[19]], 1, self.k_size[tokens[20]]),
-            (self.multiply[tokens[21]], self.filter_num5[tokens[22]], self.repeat[tokens[23]], 2, self.k_size[tokens[24]]),
-            (self.multiply[tokens[25]], self.filter_num6[tokens[26]], self.repeat[tokens[27]], 1, self.k_size[tokens[28]]),
+            (self.multiply[tokens[1]], self.filter_num1[tokens[2]],
+             self.repeat[tokens[3]], 2, self.k_size[tokens[4]]),
+            (self.multiply[tokens[5]], self.filter_num1[tokens[6]],
+             self.repeat[tokens[7]], 2, self.k_size[tokens[8]]),
+            (self.multiply[tokens[9]], self.filter_num2[tokens[10]],
+             self.repeat[tokens[11]], 2, self.k_size[tokens[12]]),
+            (self.multiply[tokens[13]], self.filter_num3[tokens[14]],
+             self.repeat[tokens[15]], 2, self.k_size[tokens[16]]),
+            (self.multiply[tokens[17]], self.filter_num3[tokens[18]],
+             self.repeat[tokens[19]], 1, self.k_size[tokens[20]]),
+            (self.multiply[tokens[21]], self.filter_num5[tokens[22]],
+             self.repeat[tokens[23]], 2, self.k_size[tokens[24]]),
+            (self.multiply[tokens[25]], self.filter_num6[tokens[26]],
+             self.repeat[tokens[27]], 1, self.k_size[tokens[28]]),
         ]
 
-        assert self.block_num < 7, 'block number must less than 7, but receive block number is {}'.format(self.block_num)
+        assert self.block_num < 7, 'block number must less than 7, but receive block number is {}'.format(
+            self.block_num)
 
         # the stride = 2 means downsample feature map in the convolution, so only when stride=2, block_num minus 1,
         # otherwise, add layers to params_list directly.
@@ -136,10 +172,11 @@ class MobileNetV2Space(SearchSpaceBase):
 
             # if output_size is 1, add fc layer in the end
             if self.output_size == 1:
-                input = fluid.layers.fc(input=input,
-                                 size=self.class_dim,
-                                 param_attr=ParamAttr(name='fc10_weights'),
-                                 bias_attr=ParamAttr(name='fc10_offset'))
+                input = fluid.layers.fc(
+                    input=input,
+                    size=self.class_dim,
+                    param_attr=ParamAttr(name='fc10_weights'),
+                    bias_attr=ParamAttr(name='fc10_offset'))
             else:
                 assert self.output_size == input.shape[2], \
                           ("output_size must EQUAL to input_size / (2^block_num)."
@@ -150,7 +187,6 @@ class MobileNetV2Space(SearchSpaceBase):
 
         return net_arch
 
-
     def shortcut(self, input, data_residual):
         """Build shortcut layer.
         Args:
@@ -161,7 +197,6 @@ class MobileNetV2Space(SearchSpaceBase):
         """
         return fluid.layers.elementwise_add(input, data_residual)
 
-
     def inverted_residual_unit(self,
                                input,
                                num_in_filter,
@@ -222,15 +257,7 @@ class MobileNetV2Space(SearchSpaceBase):
             out = self.shortcut(input=input, data_residual=out)
         return out
 
-    def invresi_blocks(self,
-                       input,
-                       in_c,
-                       t,
-                       c,
-                       n,
-                       s,
-                       k,
-                       name=None):
+    def invresi_blocks(self, input, in_c, t, c, n, s, k, name=None):
         """Build inverted residual blocks.
         Args:
             input: Variable, input.
@@ -268,5 +295,3 @@ class MobileNetV2Space(SearchSpaceBase):
                 expansion_factor=t,
                 name=name + '_' + str(i + 1))
         return last_residual_block
-
-
diff --git a/paddleslim/nas/searchspacebase.py b/paddleslim/nas/search_space/search_space_base.py
similarity index 100%
rename from paddleslim/nas/searchspacebase.py
rename to paddleslim/nas/search_space/search_space_base.py
index cc1d462aca3b81c231df53ec2b5995cbb1deb5d5..a68ec63acbb90191c931508ed96e1bb2d8261e48 100644
--- a/paddleslim/nas/searchspacebase.py
+++ b/paddleslim/nas/search_space/search_space_base.py
@@ -14,6 +14,7 @@
 
 __all__ = ['SearchSpaceBase']
 
+
 class SearchSpaceBase(object):
     """Controller for Neural Architecture Search.
     """
@@ -41,4 +42,3 @@ class SearchSpaceBase(object):
             list<layers> 
         """
         raise NotImplementedError('Abstract method.')
-
diff --git a/paddleslim/nas/searchspacefactory.py b/paddleslim/nas/search_space/search_space_factory.py
similarity index 89%
rename from paddleslim/nas/searchspacefactory.py
rename to paddleslim/nas/search_space/search_space_factory.py
index 10d076e8722a89cb46bac94360b1968e1de9e33a..11d8377d9056eddbeed43a6ff3f1aa67c6cf664c 100644
--- a/paddleslim/nas/searchspacefactory.py
+++ b/paddleslim/nas/search_space/search_space_factory.py
@@ -12,7 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from searchspace.registry import SEARCHSPACE
+from search_space_registry import SEARCHSPACE
+
+__all__ = ["SearchSpaceFactory"]
+
 
 class SearchSpaceFactory(object):
     def __init__(self):
@@ -29,8 +32,7 @@ class SearchSpaceFactory(object):
             model space(class)
         """
         cls = SEARCHSPACE.get(key)
-        space = cls(config['input_size'], config['output_size'], config['block_num'])
+        space = cls(config['input_size'], config['output_size'],
+                    config['block_num'])
 
         return space
-
-
diff --git a/paddleslim/nas/searchspace/__init__.py b/paddleslim/nas/search_space/search_space_registry.py
similarity index 86%
rename from paddleslim/nas/searchspace/__init__.py
rename to paddleslim/nas/search_space/search_space_registry.py
index d1b5c527794b03967e6ce77f8bb16e883c06dbbf..2fea80fba4c908759e6123d3d898e94d7ef54c42 100644
--- a/paddleslim/nas/searchspace/__init__.py
+++ b/paddleslim/nas/search_space/search_space_registry.py
@@ -12,4 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from .mobilenetv2_space import MobileNetV2Space
+from ...core import Registry
+
+__all__ = ["SEARCHSPACE"]
+
+SEARCHSPACE = Registry('searchspace')
diff --git a/paddleslim/nas/searchspace/registry.py b/paddleslim/nas/searchspace/registry.py
deleted file mode 100644
index 33fb7212e99c886e4ad720f21db145e6f0e2443f..0000000000000000000000000000000000000000
--- a/paddleslim/nas/searchspace/registry.py
+++ /dev/null
@@ -1,5 +0,0 @@
-import sys
-sys.path.append('..')
-from utils.registry import Registry
-
-SEARCHSPACE = Registry('searchspace')
diff --git a/paddleslim/nas/test_searchspace.py b/paddleslim/nas/test_searchspace.py
deleted file mode 100644
index 4761bf36e2722dfed83acfd69621a4e586a2ed93..0000000000000000000000000000000000000000
--- a/paddleslim/nas/test_searchspace.py
+++ /dev/null
@@ -1,36 +0,0 @@
-# Copyright (c) 2019  PaddlePaddle Authors. All Rights Reserved.
-#
-# Licensed under the Apache License, Version 2.0 (the "License"
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-import paddle.fluid as fluid
-from searchspacefactory import SearchSpaceFactory
-if __name__ == '__main__':
-    # if output_size is 1, the model will add fc layer in the end.
-    config = {'input_size': 224, 'output_size': 7, 'block_num': 5}
-    space = SearchSpaceFactory()
-    
-    my_space = space.get_search_space('MobileNetV2Space', config)
-    model_arch = my_space.token2arch()
-    
-    train_prog = fluid.Program()
-    startup_prog = fluid.Program()
-    with fluid.program_guard(train_prog, startup_prog):
-        input_size= config['input_size']
-        model_input = fluid.layers.data(name='model_in', shape=[1, 3, input_size, input_size], dtype='float32', append_batch_size=False)
-        print('input shape', model_input.shape)
-        predict = model_arch(model_input)
-        print('output shape', predict.shape)
-        
-
-    #for op in train_prog.global_block().ops:
-    #    print(op.type)
diff --git a/tests/test_searchspace.py b/tests/test_searchspace.py
new file mode 100644
index 0000000000000000000000000000000000000000..5e3557bbfc93b277fbc87339bcf6be605d313456
--- /dev/null
+++ b/tests/test_searchspace.py
@@ -0,0 +1,45 @@
+# Copyright (c) 2019  PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import sys
+sys.path.append("../")
+import unittest
+import paddle.fluid as fluid
+from paddleslim.nas import SearchSpaceFactory
+
+
+class TestSearchSpaceFactory(unittest.TestCase):
+    def test_factory(self):
+        # if output_size is 1, the model will add fc layer in the end.
+        config = {'input_size': 224, 'output_size': 7, 'block_num': 5}
+        space = SearchSpaceFactory()
+
+        my_space = space.get_search_space('MobileNetV2Space', config)
+        model_arch = my_space.token2arch()
+
+        train_prog = fluid.Program()
+        startup_prog = fluid.Program()
+        with fluid.program_guard(train_prog, startup_prog):
+            input_size = config['input_size']
+            model_input = fluid.layers.data(
+                name='model_in',
+                shape=[1, 3, input_size, input_size],
+                dtype='float32',
+                append_batch_size=False)
+            print('input shape', model_input.shape)
+            predict = model_arch(model_input)
+            print('output shape', predict.shape)
+
+
+if __name__ == '__main__':
+    unittest.main()