<!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title></title> < <style type="text/css"> *{margin:0; padding:0;} .left{300px; height:100%; background:#F00; position:fixed; left:0; top:0; float:left;} .right{margin-left:310px; height:100%; background:#0F0; display:block; border-left:1px solid #000;} </style> </head> <body> <div class="left">左侧</div> <div class="right">右侧</div> </body> </html>