The ERP system comes to existence in the period of change. In other words, the ERP system is adopted to the company with BPR project. In general, the ERP system is introduced to companies as packages rather than in-housing systems. There are several researches in IS literatures which have a conclusion that organizational context affects the performance of ERP system. This study attempts to review the organizational context from the prospective of organizational structure and change management. Regarding the organizational structure, we choose some widely known variables such as the degree of formalization and centralization. For the analysis of change management, we set the variables, which are the most importantly considered, such as the power of promotion and user participation. The extent of customizing is introduced as moderating variables between the organizational context and the implementation performance. With collected data, we performed the reliability test, the factor analysis and the regression analysis. In summary, the introduction of an information system such as ERP system has a behavioral and organizational impact. The organizational change may breed resistance and opposition and can lead to the failure of the system. Therefore, implementation of the system requires careful change management, active involvement of users and high level of management support.