In the latest electrical consuming generation, computers are still mainly tools for paperwork and game platforms, and tablet PC field and smart phone field are two new fields with powerfully market potential. With a high degree of integration and user friendly interfaces, smart phones have become very popular among the general public. Using various sensors, touch pad, and screen of a smart phone, and designing a friendly control interface with software on it, we can achieve the goal that the computer users can interact with a computer via a smart phone. Therefore, this paper discusses the experiment of using a smart phone as a game controller. Through this attempt, we can get some idea and experience from the experiment to simplify the design of smart phones and improve it to develop a controller mainly used with computers or a new game controller.