diff --git a/README.md b/README.md
index edda40a..77b088b 100644
--- a/README.md
+++ b/README.md
@@ -1,28 +1,54 @@
 Slack-to-IRC Bridge
 ===================
 
-This code is for slack to IRC bridge, also vice versa. You can build personal IRC client with slack.
+This code is for slack to IRC bridge, also vice versa. You can build personal IRC client with slack. Original code is forked from https://github.com/voldyman/slack-irc-bridge.
 
 Not Implemented
 ===============
 
-a
+not implemented IRC's user listing browsing. also, no DCC or chat function. only for generic channel chat.
 
 Build
 =====
-just clone source, ```go get`` and ```go build```
+just clone source, ```go get``` and ```go build```.
 
 after build, you must edit bot.config file to complete setup.
 
 Configuration
 =============
 
-bot.config file is json format.
-
-You can get your slack token from https://api.slack.com/web
+default file name is bot.config. if you want to use another name, just add file name as command parameter like ```./slack-irc-bridge foo.cfg```
+
+bot.config file is json format. you can check it sample.
+
+* You can get your slack token from https://api.slack.com/web
+
+```
+{
+    "bridges":[
+        {"slack":"#general", "irc":"#foo"},
+        {"slack":"#slack-channel2", "irc": "#bar"}
+    ],
+    "irc": {
+        "server": "irc.freenode.org:6667",
+        "nick" : "bot-nickname",
+        "relay_nick": true
+    },
+    "slack": {
+        "url": "https://foo.slack.com",
+        "token": "token_here"
+    }
+}
+```
+* irc/relay-nick is bool option. if you set true, bot will show your slack nick to IRC. if you use slack as single IRC client, turn off option.
+* irc/server is IRC server option. this bot doesn't translate code page, so if you are in specific locale environment, use UTF-8 server.
 
 Usage
 =====
+```
+./slack-irc-bridge  [configuratio_file]
+```
+
 
 If you want to use slack as your personal IRC client, -> make channel in slack, mapping to irc channel. (set off relay option)
 if you want to migrate from IRC to slack, -> make this code run as just bridge. also, you can build automatic invite script.