<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
</head>
<style>
div{width:20px;height:20px;background: red; position:absolute;}
</style>
<body style="height:3000px">
<div ></div>
<div ></div>
<div ></div>
<div ></div>
<div ></div>
<div ></div>
<div ></div>
<div ></div>
<div ></div>
<div ></div>
<div ></div>
<div ></div>
</body>
</html>
<script>
function getPos(ev){
var scrollTop = document.documentElement.scrollTop||document.body.scrollTop;
var scrollLeft = document.documentElement.scrollLeft||document.body.scrollLeft;
return {x:ev.clientX+scrollLeft,y:ev.clientY+scrollTop}
}
document.onmousemove = function(ev){
var oEvent = ev||event;
var pos = getPos(event);
var oDiv = document.getElementsByTagName("div");
for(var i=oDiv.length-1;i>0;i--){
oDiv[i].style.left = oDiv[i-1].offsetLeft+"px";
oDiv[i].style.top = oDiv[i-1].offsetTop+"px";
}
oDiv[0].style.left = pos.x+"px";
oDiv[0].style.top = pos.y+"px";
}
</script>
原文：http://www.cnblogs.com/dcwq/p/4784117.html