找了些网上的办法试了都不行test.htm:
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<script src="Scripts/jquery.js" type="text/javascript"></script>
<script src="Scripts/jquery.form.js" type="text/javascript"></script>
<script>
var options = { 
beforeSubmit:  showRequest,  // pre-submit callback 
success:       showResponse  // post-submit callback 
}; 
function showRequest(formData, jqForm, options) { 
    var queryString = $.param(formData); 
    //alert('About to submit: \n\n' + queryString); 
    return true; 

function showResponse(responseText, statusText)  { 
    alert('status: ' + statusText + '\n\nresponseText: \n' + responseText + 
        '\n\nThe output div should have already been updated with the responseText.'); 

function ajaxform(form){
$(form).ajaxSubmit(options);
}
</script>
<title>无标题文档</title>
</head><body>
<form name="newsform" method="post" action="test.jsp">
  <textarea name="content" id="content" cols="45" rows="5"></textarea>
  <input type="button" name="button" id="button" value="按钮" onclick="ajaxform(newsform)" />
</form>
</body>
</html>test.jsp:
<%
String content=request.getParameter("content");
out.print("test.jsp get : "+content);
%>提交结果出现乱码,英文正常。。