<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>this is a page</title>
<style type="text/css">
div{width: 200px;
height: 200px;
background-color: aqua;
position: relative;}
.span{width: 200px;
height: 30px;
background: red;
display: block;
position: absolute;
bottom: 0px;
text-align: center;
display: none;}
div:hover span{display: block;}
</style>
</head>
<body>
<div>
<span class="span">PHP</span>
</div>
</body>
</html>原文：http://my.oschina.net/dongdong11019/blog/520036