The study aims to investigate the effects of social anxiety and self-discrepancy on the internet game flow of adolescents, and to explore the moderating effect of self-discrepancy on the relationship between social anxiety and internet game flow. For this purpose, questionnaires on social anxiety, self-discrepancy and internet game flow were administered to 900 middle and high school students in the Gyeonggi region. The data were analyzed through frequency analysis, t-test, Pearson's correlation analysis, stepwise multiple regression analysis, and hierarchical regression analysis using SPSS Win 21. The major findings of the research are as follows. First, social anxiety and internet game flow of adolescents showed a significant difference by gender. The level of social anxiety was higher for girls than that of boys, while the level of internet game flow was higher for boys than that of girls. Self-discrepancy showed a significant difference by grade. The level of self-discrepancy was higher for middle school students than high school students. Second, self-discrepancy was the most significant predictor of the internet game flow in adolescents. Also, gender and social anxiety were significant predictors. Third, the moderating effect of self-discrepancy was found in the relationship between social anxiety and internet game flow in adolescents.