diff --git a/python/paddle/fluid/tests/test_detection.py b/python/paddle/fluid/tests/test_detection.py
index b8743debe214e09d4f327b526bfde3e4b856277c..b863eb8d72a0ec61e5c1c3a42cceab7373852dbb 100644
--- a/python/paddle/fluid/tests/test_detection.py
+++ b/python/paddle/fluid/tests/test_detection.py
@@ -484,7 +484,7 @@ class TestYoloDetection(unittest.TestCase):
         program = Program()
         with program_guard(program):
             x = layers.data(name='x', shape=[30, 7, 7], dtype='float32')
-            img_size = layers.data(name='x', shape=[2], dtype='int32')
+            img_size = layers.data(name='img_size', shape=[2], dtype='int32')
             boxes, scores = layers.yolo_box(x, img_size, [10, 13, 30, 13], 10,
                                             0.01, 32)
             self.assertIsNotNone(boxes)