diff --git a/README.md b/README.md
index 661fc6e..3561a7f 100644
--- a/README.md
+++ b/README.md
@@ -29,6 +29,9 @@ Server Started 127.0.0.1:8000
 $ markline server -p 80 data.md
 Server Started 127.0.0.1:80
 
+$ markline server -w data.md
+Server Started 127.0.0.1:8000
+
 $ markline build data.md
 
 $ markline build data.md --dist _site
diff --git a/bin/markline b/bin/markline
index 3736152..bc51866 100755
--- a/bin/markline
+++ b/bin/markline
@@ -10,8 +10,7 @@ commander
   .option('build', 'build markdown to markline page.')
   .option('server', 'preview markdown to markline page.')
   .option('-p, --port [port]', 'server port for preview markline.')
-  // TODO: watch markdown file, auto reload preview page.
-  //.option('-w, --watch', 'watch markdown file change, and auto reload for preview markline.')
+  .option('-w, --watch', 'watch markdown file change, and auto reload for preview markline.')
   .option('--dist [dist]', 'build markdown file to markline static site. default is `dist` in current working directory.')
   .parse(process.argv);
 
diff --git a/index.js b/index.js
index 4782ce5..fcba8c3 100644
--- a/index.js
+++ b/index.js
@@ -3,6 +3,9 @@ var path = require("path");
 var gulp = require("gulp");
 var replace = require("gulp-replace");
 var del = require("del");
+var Event = require("events").EventEmitter;
+
+var evt = new Event();
 
 var DEFAULT_DIST = "dist";
 var DEFAULT_PORT = 8000;
@@ -35,6 +38,7 @@ function build(cwd, options){
 function server(cwd, options){
   var port = options.port || DEFAULT_PORT;
   var encode = options.encode || DEFAULT_ENCODE;
+  var watch = options.watch || false;
   var fileName = options.args.join("");
 
   if (!fs.existsSync(fileName)) {
@@ -42,15 +46,10 @@ function server(cwd, options){
     return;
   }
 
-  var http = require('http').createServer(function (req, res) {
+  var app = require('http').createServer(function (req, res) {
     var url = req.url;
 
-    if (url === "/") {
-      fs.readFile(path.join(__dirname, "template", "index.html"), encode, function(err, html){
-        res.writeHead(200, {'Content-Type': 'text/html'});
-        res.end(html.replace("{FILE_NANE}", fileName));
-      });
-    } else if (url === "/" + fileName) {
+    if (url === "/" + fileName) {
       fs.readFile(path.join(cwd, fileName), encode, function(err, markdown){
         res.writeHead(200, {'Content-Type': 'text/markdown'});
         res.end(markdown);
@@ -64,7 +63,7 @@ function server(cwd, options){
       };
 
       if (url === "/") {
-        url = "index.html";
+        url = "/index.html";
       }
 
       var ext = url.split(".");
@@ -75,7 +74,21 @@ function server(cwd, options){
 
         fs.readFile(filePath, encode, function(err, html){
           res.writeHead(200, {'Content-Type': MIME_TYPE[ext]});
-          res.end(html.replace("{FILE_NANE}", fileName));
+          if (url === "/index.html") {
+            html = html.replace('{FILE_NANE}', fileName);
+
+            if (watch) {
+              html = html.replace('</body>', [
+                  '<script src="/socket.io/socket.io.js"></script><script>',
+                  'var socket = io.connect("/");',
+                  'socket.on("reload", function() { location.reload(); });',
+                  '</script>',
+                  '</body>'
+                ].join('\n')
+              );
+            }
+          }
+          res.end(html);
         });
 
       } else {
@@ -87,6 +100,20 @@ function server(cwd, options){
   }).listen(port).on("error", function(error){
     console.error(error);
   });
+
+  if (watch){
+    var io = require('socket.io')(app);
+    io.sockets.on('connection', function(socket) {
+      socket.emit('hello', {message: 'markline'});
+
+      fs.watch(fileName, function(event, fileName) {
+        if (!socket.disconnected) {
+          socket.emit('reload', {message: fileName});
+        }
+      });
+    });
+  }
+
   console.log("Server Started 127.0.0.1:" + port);
 }
 
diff --git a/package.json b/package.json
index 922e8af..9928b94 100644
--- a/package.json
+++ b/package.json
@@ -22,7 +22,8 @@
     "commander": "~1.1.1",
     "del": "^0.1.3",
     "gulp": "^3.8.8",
-    "gulp-replace": "^0.4.0"
+    "gulp-replace": "^0.4.0",
+    "socket.io": "^1.1.0"
   },
   "devDependencies": {
     "mocha": "1.17.1",