using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.Mvc;

namespace MvcApplication1.Controllers

{

    public class Person

    {

        public string Name { get; set; }

        public int Age { get; set; }

        //public List<KeyPair> Numbers { get; set; }

        public object Numbers { get; set; }

    }

    public class KeyPair

    {

        public string Key { get; set; }

        public string Value { get; set; }

    }

    public class HomeController : Controller

    {

        //

        // GET: /Home/

        public ActionResult Index()

        {

            return View();

        }

        public void Post(Person data)

        {

            var numbers= data.Numbers as List<KeyPair>;

        }

    }

}

@{

    ViewBag.Title = "Index";

}

<button id="btn">TEST</button>

<h2>Index</h2>

<script src="~/Scripts/jquery-2.0.3.js"></script>

<script>

    var data = {

        Name: "tom",

        Age: ,

        Numbers: [{ Key: "a", Value: "A" }, { Key: "b", Value: "B" }]

    };

    $(function() {

        $("#btn").on("click", function() {

            $.ajax({

                url: "/Home/Post",

                type: "POST",

                contentType: "application/json; charset=utf-8",

                data:JSON.stringify(data),

                dataType: "Json"

            });

        });

    });

</script>