<body>

     <div>

         <select id="provinceId" >

          <option> 请选择省份</option>

         </select>

         <select id="cityId">

             <option>请选择市区</option>

         </select>

     </div>

     <script type="text/javascript">

         //用json从数据库里取一级列表的参数

         $(function () {

             $.getJSON("ErJLD/getProvince/", function (obj) {

                 $.each(obj, function (i, p) {

                     $("#provinceId").append("<option value='"+p.id+"'>" + p.areaValue + "</option>");

                 });

                 $("#provinceId").change(function () {

                     //用attr（）方法获取当前选择的option的value值（即p.id ,数据库里的id值，

                     //虽然在TestController中的getCity方法中传入的是string类型的形参，但是后来需要变换成int类型, 所以value值应该为数字）

                     var pName = $("#provinceId").attr("value");

                     $.getJSON("ErJLD/getCity?pName=" + pName, getcity);

                 });

             });

         });

         function getcity(obj) {

             $("#cityId").empty();

                         $.each(obj, function (m, v) {

                             $("#cityId").append("<option >" + v.areaValue + "</option>");

                         });

                     };

     </script>

 </body>

 Index.cshtml

 namespace Mvcproject.Controllers

 {

     //二级联动

     public class ErJLDController : Controller

     {

         ZjbEntities db = new ZjbEntities();

         //

         // GET: /Test/

         public ActionResult Index()

         {

             //pro_city province=new pro_city();

             return View();

         }

         public JsonResult getProvince() {

             List<pro_city> provinceList = (from p in db.pro_city where p.level ==  select p).ToList();

             JsonResult Jprovince = new JsonResult();

             Jprovince.Data = provinceList;

             Jprovince.JsonRequestBehavior = JsonRequestBehavior.AllowGet;

             return Jprovince;

         }

         public JsonResult getCity(string pName)

         {

             //string pid = (from p in db.pro_city where p.areaValue == pName select p.id).ToString();

             //int id = int.Parse(pid);

             int id = int.Parse(pName);

             List<pro_city> cityList = (from p in db.pro_city where p.parentId == id select p).ToList();

             JsonResult Jcity = new JsonResult();

             Jcity.Data = cityList;

             Jcity.JsonRequestBehavior = JsonRequestBehavior.AllowGet;

             return Jcity;

         }

     }

 }

 ErJLDController.cs