1. <span class="upload_file">
    2.         <span class="upload_btn">上传</span>
    3.         <input type="file" name="" id="file" value="" />
    4. </span>
    1. .upload_file{
    2.     position: relative;
    3.     width:50px;
    4.     height:20px;
    5.     text-align:center;
    6.     color:#fff;
    7.     background:#A1A1A1;
    8.     display: inline-block;
    9.     overflow: hidden;
    10. }
    11. .upload_file input{
    12.     position: absolute;
    13.     right: 0px;
    14.     top: 0px;
    15.     opacity: 0;/*为了兼容ie*/
    16.     -ms-filter: 'alpha(opacity=0)';
    17. }

    tip:ie8+.