* { margin:0px; padding:0px; } .box { width:300px; height:40px; border:1px solid #666; margin:100px; position:relative; overflow:hidden; } .list_menu { width:1200px; list-style:none; overflow:hidden; } .list_menu li { float:left; width:150px; text-align:center; height:40px; line-height:40px; } .lef,.rig { position:absolute; width:30px; text-align:center; height:40px; line-height:40px; background:#aaa; color:#fff; cursor:pointer; } .lef { top:0px; left:0px; } .rig { top:0px; right:0px; }