Messaging mechanism is a basic attribute of OO system & OO language. Asynchronous messaging mechanism using middleware is widely spread among heterogeneous and distributive network environment. Combined with GUI framework, a powerful study of multi-procedure asynchronous messaging mechanism was made. Then this paper explored the principle and realized the core callback technology without any framework or developing language. At last it fully analyzed the field of asynchronous messaging application, pointed out that even in single host inner-communication, asynchronous messaging can improve performance better and help to solve some basic and special questions.