1 <!DOCTYPE html>
2 <html>
3 <head>
4 <meta charset="UTF-8">
5 <title></title>
6
7 <style type="text/css">
8 *{
9 margin: 0px;
10 padding: 0px;
11 }
12 #nav{
13 background-color: #EEE;
14 width: 400px;
15 height: 40px;
16 margin: 0 auto;
17 }
18 ul{
19 list-style: none;
20 }
21 ul li{
22 float: left;
23 padding: 0 0;
24 line-height: 40px;
25 text-align: center;
26 position: relative;
27 }
28 a{
29 text-decoration: none;
30 color: #000000;
31 display: block;
32 padding: 0 10px;
33 }
34 a:hover{
35 color: #FFF;
36 background-color:#666666;
37 }
38 ul li ul li{
39 float: none;
40 background-color: #EEE;
41 margin-top: 2px;
42 }
43 ul li ul{
44 position: absolute;
45 left: 0px ;
46 top: 40px;
47 display: none;
48
49 }
50 </style>
51 <script src="https://cdn.bootcss.com/jquery/1.10.2/jquery.min.js"></script>
52 <script>
53 $(function(){
54 $('.navmenu').mousemove(function(){
55 $(this).children('ul').show();
56 });
57 $('.navmenu').mouseout(function(){
58 $(this).children('ul').hide();
59 });
60 });
61 </script>
62 </head>
63 <body>
64 <div id="nav">
65 <ul>
66 <li class="navmenu"><a href="#">首页</a></li>
67 <li class="navmenu"><a href="#">课程大厅</a>
68 <ul>
69 <li><a href="#">jQuery</a></li>
70 <li><a href="#">javaScript</a></li>
71 </ul>
72 </li>
73 <li><a href="#">学习中心</a></li>
74 <li><a href="#">经典案例</a></li>
75 <li><a href="#">关于我们</a></li>
76 </ul>
77 </div>
78 </body>
79 </html>
![](https://images2018.cnblogs.com/blog/1456804/201808/1456804-20180815141221155-706781513.gif)