<!DOCTYPE HTML>
<html lang="en-US">
<head>
<meta charset="UTF-8">
<title>Ball</title>
<style type="text/css">
</style>
<script type="text/javascript" src="jquery-1.8.0.min.js"></script>
<script type="text/javascript">
$ (function ()
{
$ ("table tr :nth-child(1)").each (function (i, dom)
{
alert ($ (this).html ());
});
});
</script>
</head>
<body>
<table>
<tr>
<th>111</th>
<th>333</th>
</tr>
<tr>
<td>222</td>
<td>355</td>
</tr>
</table>
</body>
</html>