diff --git a/README.md b/README.md
index 54be102b0..42f63be62 100755
--- a/README.md
+++ b/README.md
@@ -5,8 +5,9 @@ SRS(SIMPLE RTMP Server) over state-threads created in 2013.
 
 SRS is a simple, [RTMP](https://github.com/winlinvip/simple-rtmp-server/wiki/DeliveryRTMP)/[HLS](https://github.com/winlinvip/simple-rtmp-server/wiki/DeliveryHLS), 
 [high-performance](https://github.com/winlinvip/simple-rtmp-server/wiki/Performance), single/multiple(plan) processes, edge(plan)/origin live server, 
-compile depends on [st](http://sourceforge.net/projects/state-threads), [ssl](http://www.openssl.org/) and [http-parser](https://github.com/joyent/http-parser), 
-use [nginx](http://nginx.org/), [ffmpeg](http://ffmpeg.org/) and [cherrypy](http://www.cherrypy.org/) as external tools.
+compile depends on [st](http://sourceforge.net/projects/state-threads)(required), [ssl](http://www.openssl.org/) and [http-parser](https://github.com/joyent/http-parser), 
+use [nginx](http://nginx.org/), [ffmpeg](http://ffmpeg.org/) and [cherrypy](http://www.cherrypy.org/) as external tools. that is, only need st to run srs for 
+minimum run. see [Build](https://github.com/winlinvip/simple-rtmp-server/wiki/Build).
 
 SRS supports [vhost](https://github.com/winlinvip/simple-rtmp-server/wiki/RtmpUrlVhost), 
 rtmp([encoder push](https://github.com/winlinvip/simple-rtmp-server/wiki/DeliveryRTMP), client/edge pull), ingester(srs pull),