In this paper, we refer to positive effect and negative effect of game. And we inquire the recent trend of edutainment that emphasizes charm of game and educational effect at the same time. Because the simulation game and the role-playing game have strong toxication, the limitation of computer use is essential. Therefore, we present dynamic computer using-time control system for prevention of game toxicaton and for activity of educational contents. The method considered in this paper increases computer using-time n proportion to using of educational contents. So it lead user of computer to use educational contents voluntarily.