This study investigate how the players' virtual community citizenship behavior were influence by online social identity and impression management of online game discussion forum. A questionnaire was designed for the online survey that resulted in a total of 692 valid responses. The results suggested that the player were more spontaneous involved in organizational citizenship behavior when they had higher identity on discussion forum. The player had more positive action in organizational citizenship behavior when they had higher attention on self impression management. This research is different from those past gaming community researches focus on the user's addiction and motivation, and give suggestions for future research.