diff --git a/python/paddle/fluid/metrics.py b/python/paddle/fluid/metrics.py
index f409da90c14a42c86ddd5bc4a3093fbb7cba423a..42d9aeb67ff7587fee87048e691588d2e60e37bc 100644
--- a/python/paddle/fluid/metrics.py
+++ b/python/paddle/fluid/metrics.py
@@ -13,8 +13,6 @@
 # limitations under the License.
 """
 Fluid Metrics
-
-The metrics are accomplished via Python natively.
 """
 
 from __future__ import print_function
@@ -24,6 +22,12 @@ import copy
 import warnings
 import six
 
+from .layer_helper import LayerHelper
+from .initializer import Constant
+from . import unique_name
+from .framework import Program, Variable, program_guard
+from . import layers
+
 __all__ = [
     'MetricBase',
     'CompositeMetric',
@@ -598,7 +602,7 @@ class DetectionMAP(object):
     Examples:
         .. code-block:: python
 
-            exe = fluid.executor(place)
+            exe = fluid.Executor(place)
             map_evaluator = fluid.Evaluator.DetectionMAP(input,
                 gt_label, gt_box, gt_difficult)
             cur_map, accum_map = map_evaluator.get_map_var()
@@ -624,9 +628,6 @@ class DetectionMAP(object):
                  overlap_threshold=0.5,
                  evaluate_difficult=True,
                  ap_version='integral'):
-        from . import layers
-        from .layer_helper import LayerHelper
-        from .initializer import Constant
 
         self.helper = LayerHelper('map_eval')
         gt_label = layers.cast(x=gt_label, dtype=gt_box.dtype)
@@ -692,7 +693,6 @@ class DetectionMAP(object):
             shape(tuple|list): the shape of state
         Returns: State variable
         """
-        from . import unique_name
         state = self.helper.create_variable(
             name="_".join([unique_name.generate(self.helper.name), suffix]),
             persistable=True,
@@ -717,8 +717,6 @@ class DetectionMAP(object):
             reset_program(Program|None): a single Program for reset process.
                 If None, will create a Program.
         """
-        from .framework import Program, Variable, program_guard
-        from . import layers
 
         def _clone_var_(block, var):
             assert isinstance(var, Variable)
diff --git a/python/paddle/fluid/tests/unittests/test_metrics.py b/python/paddle/fluid/tests/unittests/test_metrics.py
new file mode 100644
index 0000000000000000000000000000000000000000..ec27884cae2b0462951f6597b1b83e58d1c8af5d
--- /dev/null
+++ b/python/paddle/fluid/tests/unittests/test_metrics.py
@@ -0,0 +1,49 @@
+#   Copyright (c) 2018 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 unittest
+
+import paddle.fluid as fluid
+from paddle.fluid.framework import Program, program_guard
+
+
+class TestMetricsDetectionMap(unittest.TestCase):
+    def test_detection_map(self):
+        program = fluid.Program()
+        with program_guard(program):
+            detect_res = fluid.layers.data(
+                name='detect_res',
+                shape=[10, 6],
+                append_batch_size=False,
+                dtype='float32')
+            label = fluid.layers.data(
+                name='label',
+                shape=[10, 1],
+                append_batch_size=False,
+                dtype='float32')
+            box = fluid.layers.data(
+                name='bbox',
+                shape=[10, 4],
+                append_batch_size=False,
+                dtype='float32')
+            map_eval = fluid.metrics.DetectionMAP(
+                detect_res, label, box, class_num=21)
+            cur_map, accm_map = map_eval.get_map_var()
+            self.assertIsNotNone(cur_map)
+            self.assertIsNotNone(accm_map)
+        print(str(program))
+
+
+if __name__ == '__main__':
+    unittest.main()