<script src="Scripts/jquery-1.4.1.min.js" type="text/javascript"></script> <script type="text/javascript"> $(function () { Test("txt1"); }); function Test(id) { alert($("#" + id).val()); // alert($(id).val();); } </script> <input type="text" name="name" id="txt1" value="我是txt1的value," />