$(selector).attr({attribute:value, attribute:value ...})
<html>
<head>
<script type="text/javascript" src="/jquery/jquery.js"></script>
<script type="text/javascript">
$(document).ready(function(){
$("button").click(function(){
$("img").attr({width:"50",height:"80"});
});
});
</script>
</head>
<body>
<img src="/i/eg_smile.gif" />
<br />
<button>设置图像的 width 和 height 属性</button>
</body>
</html>