diff --git a/llvm-build/README.md b/llvm-build/README.md
index 1a256676fd34fecd14cc1c6b45cdb631897bd16a..af02c4c96918eabf23414d5d6a60805943c9d680 100644
--- a/llvm-build/README.md
+++ b/llvm-build/README.md
@@ -14,6 +14,13 @@ This readme briefly describes the functionality of our LLVM toolchain and how to
 Ubuntu >= 16.04  
 MacOS X >= 10.15.4  
 
+### Environmental preparation 
+
+ubuntu 
+sudo apt-get install build-essential swig python3-dev libedit-dev libncurses5-dev binutils-dev gcc-multilib  
+mac 
+brew install swig  git-lfs java coreutils wget 
+
 </br>
 
 ### Get Code