<div>
 <select id="selectSM">
  <option>选择A</option>
  <option>选择B</option>
  <option>选择C</option>
 </select>
</div>

function IninDepart(){
 $("#selectSM").remove();//清空select列表数据
 var state = 1;
 $.ajax({
  type : "POST",
  url : "<%=basePath%>/getItemDepartList.do",
  dataType : "JSON",
  data : {},
 success : function(msg)
 {
  $("#selectSM").prepend("<option value='0'>请选择</option>");//添加第一个option值
  for (var i = 0; i < msg.rows.length; i++) {
  //如果在select中传递其他参数，可以在option 的value属性中添加参数
  //$("#selectSM").append("<option value='"+msg.rows[i].id+"'>"+msg.rows[i]+"</option>");
  $("#selectSM").append("<option>"+msg.rows[i]+"</option>");
 }
 },error:function(){
 alertLayer("获取数据失败","error");
 }
 });
}

public JSONObject getItemDepartList(HttpServletRequest request) throws Exception{
 //查询select数据
 List<Map<String, Object list = appServices.getAppList();
 System.out.println("list::::::::" + list);
 //获取数据存放到数组
 String[] depart = null;
 for (Map<String, Object> map : list) {
  for (String k : map.keySet()) {
   depart = ((String) map.get(k)).split(",");
   System.out.println("depart::::::::" + depart);
  }
 }
 //去除数组中重复数据，存放到list
 List<String> strList = new ArrayList<String>();
 for (int i=0; i<depart.length; i++) {
  if(!strList.contains(depart[i])) {
   strList.add(depart[i]);
  }
 }
 System.out.println("strList::::::::" + strList);
 jsonObject.put("rows", strList);
 return jsonObject;
}

//select 的change事件用了获取下拉列表的值
$(document).on("change","#selectSM",function(){
  //获取选择的值
  var condition = $(this).val();
  //其他操作
});