This study analyzed the problem of internet game addiction of adolescents, which have recently been considered as serious social problem associated with internet environment, in the developmental perspective and relation with family function by using the "research on the actual condition of children and adolescents online games and family leisure 2009." The object of the study is students and parents from grade 7 to 9 of middle school nationwide. For the data analysis methods, frequency analysis and structural equation analysis were conducted by using SPSS 18.0 and AMOS 16.0. In the result of the study, parents' open type communication had negative effect on game addiction, and parents' problem type communication had positive effect; among the influences of parents' open type and problem type communications on game addictions, it was shown that family function (family cohesion and family adaptation) had negative mediated effect. These findings indicated that when family played its role properly, adolescents were able to escape from the game addiction, and such influence is very powerful. The result offers significant implications in the modern society where communication with parents is insufficient, emphasizing the need to better communication between family members.