diff --git a/Cargo.toml b/Cargo.toml
index 6b6c7f8f09337c0402e0e8e18d78e776dfa44e5d..835a9a92758546f6e510528727bbf7792556effb 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -3,6 +3,7 @@ name = "coap"
 version = "0.1.0"
 description = "A CoAP library"
 readme = "README.md"
+documentation = "http://covertness.github.io/coap-rs/coap/index.html"
 repository = "https://github.com/covertness/coap-rs"
 license = "MIT"
 authors = ["Yang Zhang <wuyingfengsui@gmail.com>"]
diff --git a/README.md b/README.md
index a7c9f7b8e36d35c651a142c4bf6d077d0b6bfced..c80402eabc47edb5f55bba873630b2391d510ff3 100644
--- a/README.md
+++ b/README.md
@@ -2,6 +2,8 @@
 
 A [Constrained Application Protocol(CoAP)](https://tools.ietf.org/html/rfc7252) library implemented in Rust.
 
+[Documentation](http://covertness.github.io/coap-rs/coap/index.html)
+
 ## Installation
 
 First add this to your `Cargo.toml`: