The purpose of this study was to investigate the effects of preschooler's self-regulation and maternal parenting behavior on preschooler's game immersion. Subjects were 253 4- to 5-year-old preschoolers(118 boys, 135 girls) and their mothers. Data were analyzed by descriptive statistics, t-test, correlation analysis and stepwise multiple regression analysis. The major findings are summarized as follows: (1) preschooler's game immersion differed from preschooler's gender. Boy preschooler had higher score than girl preschooler in game immersion. (2) Both boy and girl preschooler's game immersion was negatively correlated with preschooler's behavioral regulation and emotional regulation, maternal rational guidance, limit-setting and affection. (3) The most influential factor on boy preschooler's game immersion was behavioral regulation. On the other hand, the most influential factor on girl preschooler's game immersion was emotional regulation, and the next influential factor was maternal affection. Results of this study indicate that self-regulation enhancement program should be developed and mothers should be more affective with their preschoolers in order to prevent preschoolers' game immersion.