diff --git a/README.md b/README.md
index 44c5ba7..2bf855e 100644
--- a/README.md
+++ b/README.md
@@ -15,6 +15,6 @@ $ python main.py
 * use mouse to collect sun, select the plant cards and seed the plant 
 
 # Demo
-![demo1](https://raw.githubusercontent.com/marblexu/PythonPlantsVsZombies/master/demo/demo1.png)
-![demo2](https://raw.githubusercontent.com/marblexu/PythonPlantsVsZombies/master/demo/demo2.png)
+![demo1](https://raw.githubusercontent.com/marblexu/PythonPlantsVsZombies/master/demo/demo1.jpg)
+![demo2](https://raw.githubusercontent.com/marblexu/PythonPlantsVsZombies/master/demo/demo2.jpg)