<style?type="text/css"> ????????body?{?margin:?0;?padding:?0;?} ????????.main-2?{?width:?1000px;?background:?blue;?margin:?0?auto;?} ????????.left-2?{?width:?200px;?height:?400px;?position:?absolute;?top:?0;?left:?0;?background:?#555;?} ????????.middle-2?{?width:?500px;?height:?400px;?margin:?0?300px?0?200px;?background:?#666;?} ????????.right-2?{?width:?300px;?height:?400px;?position:?absolute;?right:?0;?top:?0;?background:?#777;?} ????</style><div?class="main-2"> ????????<div?class="left-2">200px?#555</div> ????????<div?class="middle-2">500px?#666</div> ????????<div?class="right-2">300px?#777</div> </div>應該用position定位時是以main-2為基準的,但是實際結果卻是以整個網頁為基準的.