Gender difference plays an important role of helping-seeking and supportive behavior while the players encounter win or lose situation that will affect the cooperation in the on-line game. Our research team developed a game called Strike Up, and used it to investigate the help-seeking and supportive behaviors displayed by children in the cooperative/competitive scenarios. In Strike Up, players must calculate numbers in a strategic fashion so that they can move their flags to the destination faster than their opponents. Game players' help seeking and supportive types in on-line discussion were categorized by Kappa method and data was analyzed by Kappa method, then Chi-square test was employed to examine the gender difference in different types of dialogues. The discourse analysis indicated that boys exhibited used more negative semantics. Girls appeared to display a more communal or cooperative orientation, as they used more positive, socially supported language. At the beginning of the game, boy were less willing to seek help than girls, yet, at the end, as the pressure of the competition mounted, male players became more eager to find assistance from teammates and were seen to adopt more help-seeking behaviors. The results can be implicated to increase the competition in game design to foster the help-seeking and supportive social behavior.