diff --git a/python/paddle/fluid/tests/unittests/test_directory_migration.py b/python/paddle/fluid/tests/unittests/test_directory_migration.py
index 2db60bc2430efa..edc02426766bc9 100644
--- a/python/paddle/fluid/tests/unittests/test_directory_migration.py
+++ b/python/paddle/fluid/tests/unittests/test_directory_migration.py
@@ -88,8 +88,8 @@ def test_new_directory(self):
             stderr=subprocess.PIPE)
         stdout, stderr = ps_proc.communicate()
 
-        assert "Error" not in str(stderr), "ErrorMessage:\n{}".format(
-            bytes.decode(stderr))
+        self.assertFalse("Error" in str(stderr),
+                         "ErrorMessage:\n{}".format(bytes.decode(stderr)))
 
     def test_old_directory(self):
         old_directory = [
@@ -173,7 +173,7 @@ def test_old_directory(self):
             stderr=subprocess.PIPE)
         stdout, stderr = ps_proc.communicate()
 
-        assert "Error" not in str(stdout), str(stdout)
+        self.assertFalse("Error" in str(stdout), bytes.decode(stdout))
 
 
 if __name__ == '__main__':