//public class Users { // public int Id { set; get; } // public string UName { set; get; } // public int UAge { set; get; } // } var userList = new List<Users>{ new Users{Id=1,UName="A",UAge=21}, new Users{Id=2,UName="B",UAge=21}, new Users{Id=3,UName="C",UAge=21}, new Users{Id=4,UName="D",UAge=21} }; List<System.Dynamic.ExpandoObject> objList = new List<System.Dynamic.ExpandoObject>(); int a = 10; while (a < 20) { dynamic obj = new System.Dynamic.ExpandoObject(); obj.ID = a; obj.FirstName = "Henry" + a; obj.LastName = "Cui" + a; obj.Age = "age" + a; obj.Time = "time" + a; a++; objList.Add(obj); //objList.Count(); } var temp1 = (from u in objList select u).ToList(); var temp = (from u in userList select u).ToList(); return new { Reslut = "succss", Rows = temp, RowsNew = temp1 };