diff --git a/python/paddle/fluid/tests/unittests/test_imperative_ptb_rnn.py b/python/paddle/fluid/tests/unittests/test_imperative_ptb_rnn.py
index 3b602303ae9a183c7b66f5613321f58898fdfcc2..460ba65a48c863315cda4847aee1b4e2366bba96 100644
--- a/python/paddle/fluid/tests/unittests/test_imperative_ptb_rnn.py
+++ b/python/paddle/fluid/tests/unittests/test_imperative_ptb_rnn.py
@@ -59,7 +59,7 @@ class SimpleLSTMRNN(fluid.imperative.Layer):
                 dtype="float32",
                 default_initializer=fluid.initializer.UniformInitializer(
                     low=-self._init_scale, high=self._init_scale))
-            self.weight_1_arr.append(weight_1)
+            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(
@@ -67,7 +67,7 @@ class SimpleLSTMRNN(fluid.imperative.Layer):
                 shape=[self._hidden_size * 4],
                 dtype="float32",
                 default_initializer=fluid.initializer.Constant(0.0))
-            self.bias_arr.append(bias_1)
+            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 = []
@@ -242,7 +242,7 @@ class TestImperativePtbRnn(unittest.TestCase):
             dy_loss = None
             last_hidden = None
             last_cell = None
-            batch_num = 50
+            batch_num = 200
 
             for i in range(batch_num):
                 x_data = np.arange(12).reshape(4, 3).astype('int64')
@@ -264,8 +264,10 @@ class TestImperativePtbRnn(unittest.TestCase):
                         dy_param_init[param.name] = param._numpy()
                 dy_loss._backward()
                 sgd.minimize(dy_loss)
-                for param in ptb_model.parameters():
-                    dy_param_updated[param.name] = param._numpy()
+                ptb_model.clear_gradients()
+                if i == batch_num - 1:
+                    for param in ptb_model.parameters():
+                        dy_param_updated[param.name] = param._numpy()
 
         with new_program_scope():
             fluid.default_startup_program().random_seed = seed
@@ -323,25 +325,28 @@ class TestImperativePtbRnn(unittest.TestCase):
                               },
                               fetch_list=fetch_list)
                 static_loss_value = out[0]
-                static_last_cell_value = out[1]
-                static_last_hidden_value = out[2]
-                for k in range(3, len(out)):
-                    static_param_updated[static_param_name_list[k - 3]] = out[k]
+                static_last_hidden_value = out[1]
+                static_last_cell_value = out[2]
 
+                if i == batch_num - 1:
+                    for k in range(3, len(out)):
+                        static_param_updated[static_param_name_list[k -
+                                                                    3]] = out[k]
+
+        self.assertTrue(np.allclose(static_loss_value, dy_loss._numpy()))
+        self.assertTrue(np.allclose(static_last_cell_value, last_cell._numpy()))
+        self.assertTrue(
+            np.allclose(static_last_hidden_value, last_hidden._numpy()))
+        for key, value in six.iteritems(static_param_init):
+            # print("static_init name: {}, value {}".format(key, value))
+            # print("dy_init name: {}, value {}".format(key, dy_param_init[key]))
+            self.assertTrue(np.allclose(value, dy_param_init[key], atol=1e-5))
+        for key, value in six.iteritems(static_param_updated):
+            # print("static name: {}, value {}".format(key, value))
+            # print("dy name: {}, value {}".format(key, dy_param_updated[key]))
             self.assertTrue(
-                np.allclose(static_loss_value.all(), dy_loss._numpy().all()))
-            self.assertTrue(
-                np.allclose(static_last_cell_value.all(),
-                            last_cell._numpy().all()))
-            self.assertTrue(
-                np.allclose(static_last_hidden_value.all(),
-                            last_hidden._numpy().all()))
-            for key, value in six.iteritems(static_param_init):
-                self.assertTrue(
-                    np.allclose(value.all(), dy_param_init[key].all()))
-            for key, value in six.iteritems(static_param_updated):
-                self.assertTrue(
-                    np.allclose(value.all(), dy_param_updated[key].all()))
+                np.allclose(
+                    value, dy_param_updated[key], atol=1e-5))
 
 
 if __name__ == '__main__':