Adolescents' addiction to game has a negative impact on the aberrance of adolescents. Although limited research has been done on the cause of game addiction, no research has been conducted on the effectiveness of prevention measures. In this paper, we propose a model to study the impact of both the motivation and prevention factors on game addiction. Surveys were conducted among middle school students in Shanghai, with 623 valid responses. The analysis results show that among all prevention factors, only attention switch has significant negative impact on game addiction, however, dissuasion and parental monitoring have positive correlation with game addiction. The rational, resource shortage and cost have no significant impacts on game addiction. The analysis results also show that among all motivation factors, mechanics, relationship and escapism have significant positive impact on addiction.