The purpose of this study is to suggest specific ways of designing educational programs for school violence prevention by applying a serious online game in Korea. To do this, first, the authors analyzed literature, programs and cases related to school violence. Second, we derived design principles for serious games from the analysis of current game contents. Finally, we wrote a design process to develop the game. A serious game for school violence prevention was specifically designed based on these design principles and processes. It was applied by registering school violence cases, processing the cases, drawing solution plans, and finishing the game. The game is intended for a game user to be self-taught and self-cured by participating in the solution process of school violence cases.