diff --git a/paddle/fluid/imperative/layer.h b/paddle/fluid/imperative/layer.h
index 2dca0b95372a0e40c8674a80eea1a8305cfafc80..294bf392d06ec2556de3a179da552c703ac7c5d2 100644
--- a/paddle/fluid/imperative/layer.h
+++ b/paddle/fluid/imperative/layer.h
@@ -127,10 +127,7 @@ class VarBase {
 
  public:
   virtual ~VarBase() {
-    if (block_ && !persistable_) {
-      block_->RemoveVar(name_);
-    }
-
+    // TODO(minqiyang): remove var desc from block desc
     if (var_) {
       delete var_;
       var_ = nullptr;
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 a0504d3dbc2542e0803c0a6c9312bee21c50ca18..878c27d9344111d18e1ff27a1d4f41f8ae0df4b0 100644
--- a/python/paddle/fluid/tests/unittests/test_imperative_ptb_rnn.py
+++ b/python/paddle/fluid/tests/unittests/test_imperative_ptb_rnn.py
@@ -243,7 +243,7 @@ class TestImperativePtbRnn(unittest.TestCase):
             dy_loss = None
             last_hidden = None
             last_cell = None
-            batch_num = 200
+            batch_num = 50
 
             for i in range(batch_num):
                 x_data = np.arange(12).reshape(4, 3).astype('int64')
diff --git a/python/paddle/fluid/tests/unittests/test_imperative_resnet.py b/python/paddle/fluid/tests/unittests/test_imperative_resnet.py
index 5e5299bda5f583a8efeae46a002d08adb3a707d2..94ac3933151ac612ea9d308f0e28c73f0c067abf 100644
--- a/python/paddle/fluid/tests/unittests/test_imperative_resnet.py
+++ b/python/paddle/fluid/tests/unittests/test_imperative_resnet.py
@@ -231,7 +231,7 @@ class TestImperativeResnet(unittest.TestCase):
         seed = 90
 
         batch_size = train_parameters["batch_size"]
-        batch_num = 50
+        batch_num = 20
         with fluid.imperative.guard():
             fluid.default_startup_program().random_seed = seed
             fluid.default_main_program().random_seed = seed