<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<style type="text/css">
*{ margin:0; padding:0;}
<!--第一种-->
.Img{ 500px; height:500px; border:1px solid #000; text-align:center;}.Img span{ display:inline-block; height:100%; vertical-align:middle;}
.Img img{ vertical-align:middle;}
<!--第二种-->
.Img2{ 500px; height:500px; border:1px solid #000; display:table; position:relative; overflow:hidden; }
.Img2 span{ display:table-cell;text-align:center;vertical-align:middle;*position:absolute; left:50%; top:50%;}
.Img2 img{ *position:relative; vertical-align:top; left:-50%; top:-50%;}
</style>
</head>
<body>
<div class="Img"><!--第一种-->
<img src="images/ad04.jpg" width="200"><span></span>
</div>
<div class="Img2"><!--第二种-->
<span><img src="images/ad04.jpg" width="200"></span>
</div>
</body>
</html>