通过jquery的 $.getJSON方法能很方便的读取：代码如下。

var areadata ={
    province : [],
    city: [],
    district: []
    }
function initAreaData(){
var dataroot="/scripts/area/areas.json";
$.getJSON(dataroot, function(data){
areadata.province=data.province;
areadata.city=data.city;
areadata.district=data.district;
});

}
areas.json是json格式的数据文件：
示例如下:
{"province":[{"name":"安徽省", "code":"340000"},{"name":"北京市", "code":"110000"}],
"city":[{"name":"安庆市", "code":"340800"},{"name":"蚌埠市", "code":"340300"}],
"district":[{"name":"埇桥区", "code":"341302"},{"name":"浉河区", "code":"411502"}]}