<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title> new document </title> <meta http-equiv="Content-Type" content="text/html;charset=UTF-8" /> <meta name="author" content="" /> <meta name="keywords" content="" /> <meta name="description" content="" /> <link rel="stylesheet" type="text/css" href="" /> <style type="text/css"></style> <script type="text/javascript" src="jquery-1.7.1.min.js "></script> </head> <body> <div id="pop" style="200px;height:100px;border:1px solid red;background-color:red;"> 我是测试文字 </div> <script type="text/javascript"> showDiv($("#pop")); function showDiv(obj){ $(obj).show(); center(obj); $(window).scroll(function(){ center(obj); }); $(window).resize(function(){ center(obj); }); } function center(obj){ var windowWidth = document.documentElement.clientWidth; var windowHeight = document.documentElement.clientHeight; var popupHeight = $(obj).height(); var popupWidth = $(obj).width(); $(obj).css({ "position": "absolute", "top": (windowHeight-popupHeight)/2+$(document).scrollTop(), "left": (windowWidth-popupWidth)/2 }); } </script> </body> </html>