这个比较简单，也没啥技术问题可说的，直接上代码加效果图：
一、代码（直接COPY到.html文件即可）：
Code
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>DIV+CSS下拉菜单</title>
<style>
body{}{
background-color:white;
font-size:12px;
font-family:Arial, Helvetica, sans-serif;
margin:0px;
padding:0px;
color:white;
}
ul,li{}{
margin:0px;
padding:0px;
}
li{}{
display:inline;
list-style:none;
list-style-position:outside;
text-align:center;
font-weight:bold;
float:left;
}
a:link{}{
color:#336601;
text-decoration:none;
float:left;
width:100px;
padding:3px 5px 0px 5px;
}
a:visited{}{
color:#336601;
text-decoration:none;
float:left;
padding:3px 5px 0px 5px;
width:100px;
}
a:hover{}{
color:white;
float:left;
padding:3px 3px 0px 20px;
width:88px;
text-decoration:none;
background-color:#539D26;
}
a:active{}{
color:white;
float:left;
padding:3px 3px 0px 20px;
width:88px;
text-decoration:none;
background-color:#BD06B4;
}
#nav{}{
width:600px;
height:30px;
border-bottom:0px;
padding:0px 5px;
position:absolute;
z-index:1;
}
.list{}{
line-height:20px;
text-align:left;
padding:4px;
font-weight:normal;
}
.menu1{}{
width:120px;
height:auto;
margin:6px 4px 0px 0px;
border:1px solid #9CDD75;
background-color:#F1FBEC;
color:#336601;
padding:6px 0px 0px 0px;
cursor:hand;
overflow-y:hidden;
filter:Alpha(opacity=70);
-moz-opacity:0.7;
}
.menu2{}{
width:120px;
height:18px;
margin:6px 4px 0px 0px;
background-color:#F5F5F5;
color:#999999;
border:1px solid #EEE8DD;
padding:6px 0px 0px 0px;
overflow-y:hidden;
cursor:hand;
}
</style>
</head>
<body>
<div id="nav">
<ul>
<li class="menu2" onMouseOver="this.className='menu1'"
onMouseOut="this.className='menu2'">菜单一
<div class="list">
<a href="#">子菜单</a><br />
<a href="#">子菜单</a><br />
<a href="#">子菜单</a><br />
<a href="#">子菜单</a><br />
<a href="#">子菜单</a><br />
<a href="#">子菜单</a><br />
</div>
</li>
<li class="menu2" onMouseOver="this.className='menu1'"
onMouseOut="this.className='menu2'">菜单二
<div class="list">
<a href="#">子菜单</a><br />
<a href="#">子菜单</a><br />
<a href="#">子菜单</a><br />
<a href="#">子菜单</a><br />
<a href="#">子菜单</a><br />
<a href="#">子菜单</a><br />
</div>
</li>
<li class="menu2" onMouseOver="this.className='menu1'"
onMouseOut="this.className='menu2'">菜单三
<div class="list">
<a href="#">子菜单</a><br />
<a href="#">子菜单</a><br />
<a href="#">子菜单</a><br />
<a href="#">子菜单</a><br />
</div>
</li>
<li class="menu2" onMouseOver="this.className='menu1'"
onMouseOut="this.className='menu2'">菜单四
<div class="list">
<a href="#">子菜单</a><br />
<a href="#">子菜单</a><br />
<a href="#">子菜单</a><br />
<a href="#">子菜单</a><br />
<a href="#">子菜单</a><br />
<a href="#">子菜单</a><br />
</div>
</li>
</ul>
</div>
</body>
</html>
一、代码（直接COPY到.html文件即可）：
Code<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=gb2312" /><title>DIV+CSS下拉菜单</title><style>body{}{background-color:white;font-size:12px;font-family:Arial, Helvetica, sans-serif;margin:0px;padding:0px;color:white;}ul,li{}{margin:0px;padding:0px;}li{}{display:inline;list-style:none;list-style-position:outside;text-align:center;font-weight:bold;float:left;}a:link{}{color:#336601;text-decoration:none;float:left;width:100px;padding:3px 5px 0px 5px;}a:visited{}{color:#336601;text-decoration:none;float:left;padding:3px 5px 0px 5px;width:100px;}a:hover{}{color:white;float:left;padding:3px 3px 0px 20px;width:88px;text-decoration:none;background-color:#539D26;}a:active{}{color:white;float:left;padding:3px 3px 0px 20px;width:88px;text-decoration:none;background-color:#BD06B4;}#nav{}{width:600px;height:30px;border-bottom:0px;padding:0px 5px;position:absolute;z-index:1;}.list{}{line-height:20px;text-align:left;padding:4px;font-weight:normal;}.menu1{}{width:120px;height:auto;margin:6px 4px 0px 0px;border:1px solid #9CDD75;background-color:#F1FBEC;color:#336601;padding:6px 0px 0px 0px;cursor:hand;overflow-y:hidden;filter:Alpha(opacity=70);-moz-opacity:0.7;}.menu2{}{width:120px;height:18px;margin:6px 4px 0px 0px;background-color:#F5F5F5;color:#999999;border:1px solid #EEE8DD;padding:6px 0px 0px 0px;overflow-y:hidden;cursor:hand;}</style></head><body><div id="nav"> <ul> <li class="menu2" onMouseOver="this.className='menu1'" onMouseOut="this.className='menu2'">菜单一 <div class="list"> <a href="#">子菜单</a><br /> <a href="#">子菜单</a><br /> <a href="#">子菜单</a><br /> <a href="#">子菜单</a><br /> <a href="#">子菜单</a><br /> <a href="#">子菜单</a><br /> </div> </li> <li class="menu2" onMouseOver="this.className='menu1'" onMouseOut="this.className='menu2'">菜单二 <div class="list"> <a href="#">子菜单</a><br /> <a href="#">子菜单</a><br /> <a href="#">子菜单</a><br /> <a href="#">子菜单</a><br /> <a href="#">子菜单</a><br /> <a href="#">子菜单</a><br /> </div> </li> <li class="menu2" onMouseOver="this.className='menu1'" onMouseOut="this.className='menu2'">菜单三 <div class="list"> <a href="#">子菜单</a><br /> <a href="#">子菜单</a><br /> <a href="#">子菜单</a><br /> <a href="#">子菜单</a><br /> </div> </li> <li class="menu2" onMouseOver="this.className='menu1'" onMouseOut="this.className='menu2'">菜单四 <div class="list"> <a href="#">子菜单</a><br /> <a href="#">子菜单</a><br /> <a href="#">子菜单</a><br /> <a href="#">子菜单</a><br /> <a href="#">子菜单</a><br /> <a href="#">子菜单</a><br /> </div> </li> </ul></div></body></html>
二、效果图：
解释一下这里纯洁的意思是指没有包含太多的JS，FLASH这类东西^_^
OK，完工了，希望能给大家带来一些帮助，THANKS……