diff --git a/README.md b/README.md
index 5ee289e..eea457f 100644
--- a/README.md
+++ b/README.md
@@ -28,7 +28,7 @@ To know more about the details, please refer to our related paper:)
 
 ## 1. Prerequisites
 ### 1.1 **Ubuntu** and **ROS**
-Ubuntu >= 18.04.
+==Ubuntu >= 18.04 (Ubuntu 16.04 is not supported)==
 
 ROS    >= Melodic. [ROS Installation](http://wiki.ros.org/ROS/Installation)