The purpose of this study is twofold: first, to identify the factors affecting the relationships between the organizational context for work innovation(organizational citizenship behaviors, IS innovation resistance, and user IT capability) and the intention of ERP extension usage, and second, to examine the mediating effect of the ERP performance on the relationships between the ERP adaptation and the intention of ERP extension usage. In order to achieve the goals of this study, data were obtained from 304 members of the seven organizations such as manufacturers, distributors and service industries, and were analyzed by using SPSS 12.0 and AMOS 5.0. The study results are as follows. There were positive effects of the organizational citizenship behaviors and the user IT capability on the change management activity. The IS innovation resistance had a negative effects on the change management activity. The change management activity had a positive effect on the ERP adaptation. The ERP adaptation had a positive effect on the ERP performance and the intention of ERP extension usage. The ERP performance had a positive effect on the intention of ERP extension usage. In addition, there was a partial mediating effect of the ERP performance on the relationships between ERP adaptation and intention of ERP extension usage. Based on these findings, the implications and limitations of the study were presented including some directions for future studies.