------解决方案-------------------- 用这个方法AddRange
------解决方案-------------------- list1.Union(list2);
------解决方案-------------------- 合并到一个list后绑定
------解决方案-------------------- lz是不是想list1作为dropdownlist的text,list2是dropdownlist的value啊 List<string> list1 = new List<string>() { "a", "b", "c" }; List<string> list2 = new List<string>() { "1", "2", "3" }; var source = (from text in list1 from value in list2 where list1.IndexOf(text) == list2.IndexOf(value) select new ListItem() { Text = text, Value = value }).ToArray(); DropDownList1.DataSource = source; DropDownList1.DataBind();