diff --git a/python/paddle/fluid/framework.py b/python/paddle/fluid/framework.py
index 14b8339df05159d9914536b0efda73647df576b0..4ff769dd48b3be031e89985ecefe63e59b3f5fe7 100644
--- a/python/paddle/fluid/framework.py
+++ b/python/paddle/fluid/framework.py
@@ -1195,7 +1195,7 @@ class Block(object):
             if not var.persistable:
                 del self.vars[name]
 
-        self.ops.clear()
+        del self.ops[:]
 
     def all_parameters(self):
         return list(self.iter_parameters())
diff --git a/python/paddle/fluid/tests/unittests/test_imperative_optimizer.py b/python/paddle/fluid/tests/unittests/test_imperative_optimizer.py
index 3bcfdac6ce49ab92f7987aac6cf1656071467a8b..bde69165250bed97b15fdee7c28d15e6803c7bec 100644
--- a/python/paddle/fluid/tests/unittests/test_imperative_optimizer.py
+++ b/python/paddle/fluid/tests/unittests/test_imperative_optimizer.py
@@ -114,11 +114,7 @@ class TestImperativeMnist(unittest.TestCase):
 
             dy_param_init_value = {}
             for epoch in range(epoch_num):
-                print("epoch", epoch)
                 for batch_id, data in enumerate(train_reader()):
-                    #  if batch_id >= batch_num:
-                    #  break
-
                     dy_x_data = np.array(
                         [x[0].reshape(1, 28, 28)
                          for x in data]).astype('float32')
@@ -186,9 +182,6 @@ class TestImperativeMnist(unittest.TestCase):
 
             for epoch in range(epoch_num):
                 for batch_id, data in enumerate(train_reader()):
-                    #  if batch_id >= batch_num:
-                    #  break
-
                     static_x_data = np.array(
                         [x[0].reshape(1, 28, 28)
                          for x in data]).astype('float32')
@@ -209,13 +202,15 @@ class TestImperativeMnist(unittest.TestCase):
                         static_param_value[static_param_name_list[i - 1]] = out[
                             i]
 
+        self.assertTrue(np.allclose(dy_x_data.all(), static_x_data.all()))
+
         for key, value in six.iteritems(static_param_init_value):
             self.assertTrue(np.allclose(value, dy_param_init_value[key]))
 
         self.assertTrue(np.allclose(static_out, dy_out))
 
         for key, value in six.iteritems(static_param_value):
-            self.assertTrue(np.allclose(value, dy_param_value[key]))
+            self.assertTrue(np.allclose(value, dy_param_value[key], atol=1e-6))
 
 
 if __name__ == '__main__':