<select>
   <option>信息一</option>
   <option>信息二</option>
   <option>信息三</option>
   <option>信息四</option>
 </select>

$(document).ready(function () {
  $.ajax({
    timeout: 3000,
    async: false,
    type: "POST",
    url: "WareHouse.ashx",
    dataType: "json",
    data: {
      warehouse: $("#issued_sub_key_c").val(),
    },
    success: function (data) {
      for (var i = 0; i < data.length; i++) {
        $("#issued_sub_key_c").append("<option>" + data[i].Name + "</option>");
      }
    }
  });
});

public string toJson(List<string> str)
    {
      StringBuilder json = new StringBuilder();

      if (str == null)
      {
        return "null";

      }

      json.Append("[");
      foreach (var item in str)
      {
        json.Append("{\"Name\":\"");
        json.Append(item);
        json.Append("\"},");
      }

      return json.ToString().Substring(0, json.ToString().LastIndexOf(",")) + "]";
    }


    /*得到并关联仓库(select标签)*/

    public void ProcessRequest(HttpContext context)
    {

      SubinventoryDC subinventorydc = new SubinventoryDC();

      List<string> list = new List<string>();

      list = subinventorydc.getAllSubinventory();

      string json = toJson(list);

      context.Response.ContentType = "text/plain";

      context.Response.Write(json);
    }

<select id="issued_sub_key_c" name="issued_sub_key_c">
 </select>