Objective: The aim of this study is to propose the contactless gesture-based interface on smart mobile devices for especially rhythm action games. Background: Most existing approaches about interactions of smart mobile games are tab on the touch screen. However that way is such undesirable for someone or for sometimes, because of the disabled person, or the inconvenience that users need to touch/tab specific devices. Moreover more importantly, new interaction can derive new possibilities from stranded game genre. Method: In this paper, I present a smart mobile game with contactless gesture-based interaction and the interfaces using computer vision technology. Discovering the gestures which are easy to recognize and research of interaction system that fits to game on smart mobile device are conducted as previous studies. A combination between augmented reality technique and contactless gesture interaction is also tried. Results: The rhythm game allows a user to interact with smart mobile devices using hand gestures, without touching or tabbing the screen. Moreover users can feel fun in the game as other games. Conclusion: Evaluation results show that users make low failure numbers, and the game is able to recognize gestures with quite high precision in real time. Therefore the contactless gesture-based interaction has potentials to smart mobile game. Application: The results are applied to the commercial game application.