HTML代碼：
<!DOCTYPE html>
<html>
<head>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs
/jquery/1.7.2/jquery.min.js"></script>
<title>side menu</title>
</head>
<body>
<div id="menu">
<div class="m-one">
<span class="m-tit">主菜單01</span>
<ul class="m-ul">
<li class="m-li">子菜單11</li>
<li class="m-li">子菜單12</li>
<li class="m-li">子菜單13</li>
</ul>
</div>
<div class="m-one">
<span class="m-tit">主菜單02</span>
<ul class="m-ul">
<li class="m-li">子菜單21</li>
<li class="m-li">子菜單22</li>
<li class="m-li">子菜單23</li>
</ul>
</div>
<div class="m-one">
<span class="m-tit">主菜單03</span>
<ul class="m-ul">
<li class="m-li">子菜單31</li>
<li class="m-li">子菜單32</li>
<li class="m-li">子菜單33</li>
</ul>
</div>
<div class="m-one">
<span class="m-tit">主菜單04</span>
<ul class="m-ul">
<li class="m-li">子菜單41</li>
<li class="m-li">子菜單42</li>
<li class="m-li">子菜單43</li>
</ul>
</div>
<div class="m-one">
<span class="m-tit">主菜單05</span>
<ul class="m-ul">
<li class="m-li">子菜單51</li>
<li class="m-li">子菜單52</li>
<li class="m-li">子菜單53</li>
</ul>
</div>
</div>
</body>
</html>CSS代碼：
#menu {}
.m-one {float:left;width:100px;height:40px;line-height:40px; text-align:center; background:#eeeeee;}
.m-one:hover{background:#dddddd;}
ul,li {list-style:none; margin:0;padding:0;}
.m-ul {background:#dddddd; display:none;}
.m-li {font-size:12px; height:25px; line-height:25px;}
.m-li:hover {background:#cccccc;}JQUERY代碼：
$(document).ready(function() {
$('.m-one').hover(
function(){$(this).children('.m-ul').slideDown(200);},
function(){$(this).children('.m-ul').slideUp(200);}
);
});
