我是这样子写的、可以参考一下

.topList{

    width:300px;

    height:180px;

    border:1px solid #E8E8E8;

    margin:0 auto;

}

.topList ul{

    list-style-type:none;

    padding:5px;

    font-size:12px;

    margin-top:-5px;

}

em{

    width:20px;

    height:16px;

    text-align:center;

    font-style:normal;

    color:#333;

    background:url(http://img.mukewang.com/53cf0fa20001d3dc00200032.jpg) no-repeat bottom center;

    display:block;

    float:left;

}

.top em{

    color:#FFF;

    background:url(http://img.mukewang.com/53cf0fa20001d3dc00200032.jpg) no-repeat top center;

}

.topList a:link,.topList a:visited{

    text-decoration: none;

    color: #888;

}

.topList a:hover,.topList a:active{

    text-decoration: none;

    color: #F00;

}