diff --git a/concurrency/channel.go b/concurrency/channel.go
index 6c75176..c610971 100644
--- a/concurrency/channel.go
+++ b/concurrency/channel.go
@@ -1,7 +1,7 @@
 // Copyright 2021 dudaodong@gmail.com. All rights reserved.
 // Use of this source code is governed by MIT license
 
-// Package concurrency contain some functions to support concurrent programming. eg, goroutine, channel, async.
+// Package concurrency contain some functions to support concurrent programming. eg, goroutine, channel.
 package concurrency
 
 import (
diff --git a/docs/concurrency.md b/docs/concurrency.md
index 5e74b18..e71848c 100644
--- a/docs/concurrency.md
+++ b/docs/concurrency.md
@@ -1,5 +1,5 @@
 # Concurrency
-Package concurrency contain some functions to support concurrent programming. eg, goroutine, channel, async.
+Package concurrency contain some functions to support concurrent programming. eg, goroutine, channel.
 
 <div STYLE="page-break-after: always;"></div>
 
diff --git a/docs/concurrency_zh-CN.md b/docs/concurrency_zh-CN.md
index ab68877..4fc41b6 100644
--- a/docs/concurrency_zh-CN.md
+++ b/docs/concurrency_zh-CN.md
@@ -1,5 +1,5 @@
 # Concurrency
-并发包包含一些支持并发编程的功能。例如：goroutine, channel, async等。
+并发包包含一些支持并发编程的功能。例如：goroutine, channel等。
 
 <div STYLE="page-break-after: always;"></div>