diff --git a/components/libc/compilers/armlibc/README.md b/components/libc/compilers/armlibc/README.md
index 8126038e4680143a3dd80d7b64f2d932c9f3f6c2..4d2a73b6bea8d8a524761436908228e9f0e00895 100644
--- a/components/libc/compilers/armlibc/README.md
+++ b/components/libc/compilers/armlibc/README.md
@@ -1,3 +1,9 @@
+# ARMLIB (Keil-MDK) porting for RT-Thread
+
+Please define RT_USING_LIBC and compile RT-Thread with Keil-MDK compiler.
+
+
+
 ## More Information
 
 https://www.keil.com/support/man/docs/armlib/
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diff --git a/components/libc/compilers/common/readme.md b/components/libc/compilers/common/readme.md
index 0cd56272ff2b65a03add637103afb72420cbe848..99797d933c7a049bd27c84e80310f47bff6d8b64 100644
--- a/components/libc/compilers/common/readme.md
+++ b/components/libc/compilers/common/readme.md
@@ -1,4 +1,4 @@
-# Attention : 
+## Attentions
 
 1. This folder is "common" for armlibc newlibc and dlib. It's not "common" for minilibc.
 
diff --git a/components/libc/compilers/dlib/README.md b/components/libc/compilers/dlib/README.md
index 846eb3f5c0846238359ba199055e4f80e9fb9e1e..acd08f90749adeb654e178c85fb577f396e74abb 100644
--- a/components/libc/compilers/dlib/README.md
+++ b/components/libc/compilers/dlib/README.md
@@ -1,4 +1,9 @@
-Dlib(IAR) porting for RT-Thread.
+# DLIB (IAR) porting for RT-Thread
 
 Please define RT_USING_LIBC and compile RT-Thread with IAR compiler.
 
+
+
+## More Information
+
+http://www.iarsys.co.jp/download/LMS2/arm/7502/ewarm7502doc/arm/doc/EWARM_DevelopmentGuide.ENU.pdf    P.130
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diff --git a/components/libc/compilers/newlib/README.md b/components/libc/compilers/newlib/README.md
new file mode 100644
index 0000000000000000000000000000000000000000..385f329a4f3600832055a94fac6eaad270e2b033
--- /dev/null
+++ b/components/libc/compilers/newlib/README.md
@@ -0,0 +1,9 @@
+# NEWLIB (GCC) porting for RT-Thread
+
+Please define RT_USING_LIBC and compile RT-Thread with GCC compiler.
+
+
+
+## More Information
+
+https://sourceware.org/newlib/libc.html#Reentrancy
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