当然可以，给你个例子

注意类前面的[xmlinclude]那部分
using System;
using System.Collections ;
using System.IO ;
using System.Xml.Serialization;
using System.Diagnostics ;
namespace Bigeagle.Model.Base
{
    /// <summary>
    /// 枚举，表示组织结构节点类型
    /// </summary>
    public enum ObjectType
    {
        Enterprise = 0 ,
        Outter ,
        Unit ,
        Department ,
        Position ,
        Duty ,
        Data
    }
    /// <summary>
    /// <br>组织结构类</br>
    /// <br>Author:    Bigeagle@163.net</br>
    /// <br>Date:    2001/12/26</br>
    /// <br>History: 2001/12/26 finished</br>
    /// <ul>2001/12/28，添加流程数组</ul>
    /// </summary>
    ///<remarks>组织结构类</remarks>
    [XmlInclude(typeof(Enterprise)), XmlInclude(typeof(Outter))