Many companies have been implementing Enterprise resource planning (ERP) systems for their organizational transformation in order to survive and achieve strategic advantages in an increasing competitive business environment. Thus, it is meaningful to identify factors that affect ERP system operation positively. Organizational citizenship behaviors (OCB) are discretionary, extra-role behaviors of employees which go beyond the prescribed formal roles, and are known as to be the contribution factors for organization performance. The purpose of this study is to develop the measurements for the OCB constructs in ERP system context and empirically test the relationships between the OCB construct and ERP system success. The four constructs - altruism, conscientiousness and courtesy, civic virtue, and sportsmanship - and fifteen measurements on the OCB were developed based on previous studies (i.e. Organ 1988) and empirically verified by confirmatory factor analysis. The results of testing the relationships between the OCB and ERP system success show that the OCB have a significant direct impact on the information quality and intention of IT innovation while they have an indirect impact on work efficiency mediated by information quality. This study enhances the OCB model into information system arena and helps better understand the user behaviors of information systems.