<!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=utf-8" />
<meta name="author" content="Nancle from CAU CS101" />
<title>jQuery图片渐变切换</title>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.1/jquery.min.js"></script>
<style type="text/css">
ul{position:relative;}
ul li{display:block; position:absolute; left:0; top:0}
img{width:480px; height:320px; border:5px solid #ccc}
</style>
</head>
<body>
<ul>
<li><img src="http://down.fpwap.com/UploadFiles/sjbz/2010/6/2010615222757.jpg" /></li>
<li><img src="http://img5.cache.netease.com/m/app/201108/31/953DDLJL.jpg" /></li>
<li><img src="http://i-imgp.fetionpic.com/fphoto/photo1/M00/41/83/rBUyIVHfdvC9LAM6AAC873sDEoo981.jpg" /></li>
<li><img src="http://img.bimg.126.net/photo/L0py2I9-0qIAd_Keov5GhQ==/1710804908448128265.jpg" /></li>
</ul>
</div>
<script>
var switchSpeed = 1000; //图片切换时间
var fadeSpeed = 1500; //渐变时间
setInterval(function(){
$('img').last().fadeOut(fadeSpeed, function(){
$(this).show().parent().prependTo($('ul'));
});
}, switchSpeed);
</script>
</body>
</html>
效果预览：http://quchen.cau.edu.cn/jsDev/gradien.html