diff --git a/README.md b/README.md
index 9ed26d4..22e804e 100644
--- a/README.md
+++ b/README.md
@@ -151,7 +151,7 @@ Move `percona-server-5.6\_5.6.31-77.0` to PhxSQL directory, rename or link as 'p
 | | Port | Port for phxsqlproxy to listen |
 | | LogFilePath  | Directory to store log |
 | | LogLevel | Log level of phxbinlogsvr |
-| | MasterEnableReadPort | Enable readonly-port in master node  |
+| | MasterEnableReadPort | Enable readonly-port in master node. If set to 0, master will forwarding readonly-port requests to one of slaves. |
 | | TryBestIfBinlogsvrDead | After the local phxbinlogsvr is dead, phxsqlproxy will try to get master information from phxbinlogsvr on other machine, if this option set to 1. |
 
 # PhxSQL Usasge
diff --git a/README.zh_cn.md b/README.zh_cn.md
index b34d8bb..8bcbc47 100644
--- a/README.zh_cn.md
+++ b/README.zh_cn.md
@@ -145,7 +145,7 @@ PhxSQL需要用到一些第三方库（glog, leveldb, protobuf, phxpaxos, colib,
 | | Port | phxsqlproxy的监听端口 |
 | | QSLogFilePath  | phxsqlproxy的日志目录 |
 | | QSLogLevel | phxsqlproxy的日志级别 |
-| | MasterEnableReadPort | Enable readonly-port in master node |
+| | MasterEnableReadPort | 是否打开master的只读端口。如果设为0，master会将只读端口的请求转发到一台slave上。 |
 | | TryBestIfBinlogsvrDead | 如果这个选项设为1，在本地phxbinlogsvr挂掉后，phxsqlproxy会重试从别的机器上的phxbinlogsvr获取master信息。 |
 
 # PhxSQL使用