省级联动

                               

                               //json对象

                               var city_json = '{"山西":["太原","临汾"],"北京":["华联","上地"]}';

                               //json对象转object

var city_obj = eval('(' + city_json + ')');

for(var key in city_obj) {
alert(key);  //北京  山西
$("#sheng").append("<option value='" + key + "'>" + key + "</option>");
}
$("#sheng").change(function() {
var now_province = $(this).val();
$("#shi").html('<option value="">请选择城市</option>');
for(var k in city_obj[now_province]) {
var now_city = city_obj[now_province][k];
$("#shi").append('<option value="' + now_city + '">' + now_city + '</option>');
}

});

或者

                         var shengs=["山西","北京"];
var shis=[["太原","临汾"],["西二旗","上地"]];
$(function(){
for(var i=0;i<shengs.length;i++){
$("#sheng").append("<option>"+shengs[i]+"</option>");
}

$("#sheng").change(function(){
 var index=0;
  for(var j=0;j<shengs.length;j++){
    $("#s").siblings().remove();
    if($(this).val()==shengs[j]){
             index=j;
         }  
       }
for(var z=0;z<shis.length;z++){              
          $("#shi").append("<option>"+shis[index][z]+"</option>");
    }


})
})

或者

                      angular.module("app", []).controller("mc", ["$scope", function(scope) {

scope.datas=["请选择---","山西","北京"];
scope.gc=function(){
if(scope.sh=="山西"){
alert("2");
scope.list=["太原","临汾","大同"];
}else if(scope.sh=="北京"){
scope.list=["海淀区","朝阳区","昌平区"];
}

}

}]);

<table ng-app="app" ng-controller="mc">
<tr>
<td> 省份：</td>
<td>
<select id="sheng" ng-change="gc()"  ng-model="sh">
<option ng-repeat="d in datas" >{{d}}</option>

</select>
</td>
</tr>
<tr>
<td> 城市：</td>
<td>
<select id="shi">
<option >请选择---</option>
<option ng-repeat="l in list"  >{{l}}</option>
</select>
</td>
</tr>
</table>