<div></div>

    <div></div>

    <div></div>

    <div></div>

div{

            width: 100px;height: 60px;background: green;

            margin: 20px;float: left;display: none;

        }

var o_div = $('div');

    var len = o_div.length;

    var count = 0;

    function overturn(){

        o_div.eq(count).fadeIn();

        count ++;

        if (count == len) {//当元素全部显示后

            clearInterval(s);

            setTimeout(function(){//过3分钟再重新执行

                s = setInterval(overturn,800);//每0.8秒出现一个元素

            },3000);

        }

        if (count > len) {

            count = 0;

            o_div.css('display','none');//当元素个数加到比元素本身个数大时，隐藏，为下一次动画做准备

        }

    }

    var s = setInterval(overturn,800);