diff --git a/README.md b/README.md
index 885ff4d..8aa7307 100644
--- a/README.md
+++ b/README.md
@@ -10,13 +10,13 @@ https://user-images.githubusercontent.com/48993524/170857367-2033c514-3c9f-4297-
 
 **Video samples generated by CogVideo**. The actual text inputs are in Chinese. Each sample is a 4-second clip of 32 frames, and here we sample 9 frames uniformly for display purposes.
 
-![Intro images](assets/intro-image.pdf)
+![Intro images](assets/intro-image.png)
 
-![More samples](assets/appendix-moresamples.pdf)
+![More samples](assets/appendix-moresamples.png)
 
 
 
 **CogVideo is able to generate relatively high-frame-rate videos.**
 A 4-second clip of 32 frames is shown below. 
 
-![high-frame-rate sample](assets/appendix-sample-highframerate.pdf)
+![High-frame-rate sample](assets/appendix-sample-highframerate.png)