diff --git a/fluid/object_detection/data/coco/download.sh b/fluid/object_detection/data/coco/download.sh
index 50bc8a6894463549a2b18197704450621e969c9d..6f262ccebb635e993b35349890a793430d9ad597 100644
--- a/fluid/object_detection/data/coco/download.sh
+++ b/fluid/object_detection/data/coco/download.sh
@@ -11,10 +11,10 @@ wget http://images.cocodataset.org/annotations/annotations_trainval2014.zip
 wget http://images.cocodataset.org/annotations/annotations_trainval2017.zip
 # Extract the data.
 echo "Extracting..."
-unzip train2014.tar
-unzip val2014.tar
-unzip train2017.tar
-unzip val2017.tar
-unzip annotations_trainval2014.tar
-unzip annotations_trainval2017.tar
+unzip train2014.zip
+unzip val2014.zip
+unzip train2017.zip
+unzip val2017.zip
+unzip annotations_trainval2014.zip
+unzip annotations_trainval2017.zip