public void TestGetWithNSub() { var rtnForGetAll = new List <User>() { new User() { Name = "Amigo", DepartmentId = 1, Department = new Department() { Name = "開發二課" } }, new User() { Name = "Ariel", DepartmentId = 1, Department = new Department() { Name = "開發一課" } }, new User() { Name = "Frank", DepartmentId = 1, Department = new Department() { Name = "開發一課" } } }; IDalService dalService = Substitute.For <IDalService>(); dalService.GetAll().Returns(rtnForGetAll.AsEnumerable()); var entities = dalService.GetAll(); foreach (var entity in entities) { Debug.WriteLine(String.Format("Name:{0}, Department:{1}", entity.Name, entity.Department.Name)); } Debug.WriteLine("Finish"); //The real test here .... }