<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<style type="text/css" media="screen">
.border_animation{position:relative;width:272px;height:182px;margin:50px auto; /*border:1px solid black;*/}
.border_animation .img_wrap{width:270px;height:180px;border:1px solid #eee}
.border_animation .border_top{position:absolute;height:1px;width:0;font-size:0;background:#000;top:0;left:0;}
.border_animation .border_right{position:absolute;height:0px;width:1px;font-size:0;background:#000;bottom:0;right:0;}
.border_animation .border_bootom{position:absolute;height:1px;width:0px;font-size:0;background:#000;right:0;bottom:0;}
.border_animation .border_left{position:absolute;height:0px;width:1px;font-size:0;background:#000;left:0;top:0;}
</style>
</head>
<body>
<div class="border_animation">
<div class="border border_top"></div>
<div class="border border_right"></div>
<div class="border border_bootom"></div>
<div class="border border_left"></div>
<div class="img_wrap">
<a target="_blank" href="#">
<img width="270" height="180" src="qq.png" />
</a>
</div>
</div>
<script src="jquery.js"></script>
<script>
$(function(){
$(".border_animation").hover(
function(){
$(".border_top").animate({'width':'272px'},500);
$(".border_right").animate({'height':'182px'},500);
$(".border_bootom").animate({'width':'272px'},500);
$(".border_left").animate({'height':'182px'},500);
},
function(){
$(".border_top").animate({'width':'0'},500);
$(".border_right").animate({'height':'0'},500);
$(".border_bootom").animate({'width':'0'},500);
$(".border_left").animate({'height':'0'},500);
})
});
</script>
</body>
</html>