This study proposes a multi-agent modeling and simulation approach using EGGBM (E-Government Group Behavior Model) to research complex group behavior in Egovernment implementation. A multi-agent simulation decision system based on Java-REPAST is developed for qualitative validation to show that EGGBM is consistent with common sense. We give an example of EGGBM application to show that EGGBM method can help decisionmakers choose appropriate decisions to improve the level of accepting information technology (LAIT) of groups. Finally, we conclude that this approach could provide a new attempt for the research of group behavior in Egovernment organization.