diff --git a/skin-preview/README.md b/skin-preview/README.md
index a414ab7..7ab264b 100644
--- a/skin-preview/README.md
+++ b/skin-preview/README.md
@@ -11,25 +11,25 @@ Equality, Freedom, Passion
 
 ----------------------------
 * [bootstyle](https://github.com/b3log/solo-third-skins/tree/master/bootstyle)
-![bootstyle](https://github.com/b3log/solo-third-skins/blob/master/skin-preview/bootstyle.png?raw=true)
+![bootstyle](https://github.com/b3log/solo-third-skins/blob/master/skin-preview/bootstyle.jpg?raw=true)
 
 * [dashu03](https://github.com/b3log/solo-third-skins/tree/master/dashu03)
-![dashu03](https://github.com/b3log/solo-third-skins/blob/master/skin-preview/dashu03.png?raw=true)
+![dashu03](https://github.com/b3log/solo-third-skins/blob/master/skin-preview/dashu03.jpg?raw=true)
 
 * [community-bubbles](https://github.com/b3log/solo-third-skins/tree/master/community-bubbles)
-![community-bubbles](https://github.com/b3log/solo-third-skins/blob/master/skin-preview/community-bubbles.png?raw=true)
+![community-bubbles](https://github.com/b3log/solo-third-skins/blob/master/skin-preview/community-bubbles.jpg?raw=true)
 
 * [Dot-B](https://github.com/b3log/solo-third-skins/tree/master/Dot-B)
-![Dot-B](https://github.com/b3log/solo-third-skins/blob/master/skin-preview/Dot-B.png?raw=true)
+![Dot-B](https://github.com/b3log/solo-third-skins/blob/master/skin-preview/Dot-B.jpg?raw=true)
 
 * [Shawn](https://github.com/b3log/solo-third-skins/tree/master/Shawn)
-![Shawn](https://github.com/b3log/solo-third-skins/blob/master/skin-preview/Shawn.png?raw=true)
+![Shawn](https://github.com/b3log/solo-third-skins/blob/master/skin-preview/Shawn.jpg?raw=true)
 
 * [Coda](https://github.com/b3log/solo-third-skins/tree/master/Coda)
-![Coda](https://github.com/b3log/solo-third-skins/blob/master/skin-preview/Coda.png?raw=true)
+![Coda](https://github.com/b3log/solo-third-skins/blob/master/skin-preview/Coda.jpg?raw=true)
 
 * [5styles](https://github.com/b3log/solo-third-skins/tree/master/5styles)
-![5styles](https://github.com/b3log/solo-third-skins/blob/master/skin-preview/5styles.png?raw=true)
+![5styles](https://github.com/b3log/solo-third-skins/blob/master/skin-preview/5styles.jpg?raw=true)
 
 * [idream](https://github.com/b3log/solo-third-skins/tree/master/idream)
-![idream](https://github.com/b3log/solo-third-skins/blob/master/skin-preview/idream.png?raw=true)
+![idream](https://github.com/b3log/solo-third-skins/blob/master/skin-preview/idream.jpg?raw=true)