diff --git a/README.md b/README.md
index 2784fec..ec4d0b6 100644
--- a/README.md
+++ b/README.md
@@ -1,8 +1,12 @@
 
 eval
 ===
+[![docs](https://docs.rs/eval/badge.svg?version=0.1.1 "docs")](https://docs.rs/eval)
+
 Expression evaluator for Rust.
 
+## [Document](https://docs.rs/eval)
+
 ## Features
 Supported operators: `!` `!=` `""` `''` `()` `[]` `,` `>` `<` `>=` `<=` `==`
 `+` `-` `*` `/` `%` `&&` `||` `n..m`.