diff --git a/README.md b/README.md
index a1f82d7e30661d7851f11f036b62a1a1fe32d217..370dbe23a2c7855d37bed9b2a13f48bb69657d66 100644
--- a/README.md
+++ b/README.md
@@ -8,7 +8,7 @@
- windows:PHP>=5.4
- - linux|mac:PHP>=5.4(依赖pcntl和posix扩展,一般默认已安装;推荐安装event扩展,性能更高,非硬性要求)
+ - linux|mac:PHP>=5.4(依赖pcntl和posix扩展,一般默认已安装;推荐安装event扩展,性能更高,且支持毫秒级定时,非硬性要求)
## 【二】 Composer安装