<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.6.2/jquery.min.js"></script>
<script>
$(function(){
    var p = $("p").filter(function(){return $(this).css("visibility")=="hidden";}).html();
    alert(p)    
})
</script>
<p style="visibility:hidden">xxxx</p>

------解决方案--------------------
HTML code
<script src="http://ajax.aspnetcdn.com/ajax/jQuery/jquery-1.4.4.min.js"></script>
  
<p style="display:none">ddd</p>
<p style="visibility:hidden">vvv</p>
<script>
    alert($( "p[style*=visibility:hidden]").html());
</script>