diff --git a/dnmetis/README.md b/dnmetis/README.md
index dfffd1b..278a2e4 100644
--- a/dnmetis/README.md
+++ b/dnmetis/README.md
@@ -4,7 +4,8 @@ pip3.7.5 install python-opencv
 cd backend_C++/dnmetis_backend
 pip3.7.5 setup.py install
 ```
-Details of dnmetis_backend installation can be found in backend_C++/dnmetis_backend/README.md
+Details of dnmetis_backend installation can be found in backend_C++/dnmetis_backend/README.md. Notice that, you just need to install requirements once for a brand new Ai1-Inference environment。
+
 ## 2.Download dataset and model(.om)
 
 1.download  Imagenet-val dataset URL: http://www.image-net.org/download-imageurls