<script src="../Js/jquery-1.4.2.min.js" type="text/javascript"></script>

    <script type="text/javascript">

        $(function () {

            $("#a_doClick").click(function () {

                $("#<%=btnTest.ClientID%>").click();

            })

        })

    </script>

<a id="a_doClick">触发Button的Click事件</a>

<asp:Button runat="server" ID="btnTest" Text="测试js触发事件" OnClick="btnTest_Click" /> 

protected void btnTest_Click(object sender, EventArgs e)

       {

          Response.Redirect("http://www.baidu.com");

       }