<script language="javascript" src="jquery-1.4.2.min.js"></script>
<script type="text/javascript">
$(function(){
$("div").find("p").andSelf().addClass("border");
});
</script>
</head>
<body>
<div>
<p>First Paragraph</p>
<p>Second Paragraph</p>
</div>
</body>
</html>
使用andSelf()
<div class="border">
<p class="border">First Paragraph</p>
<p class="border">Second Paragraph</p>
</div>