Todays, e-Government uses ICT to promote better quality products, more efficient services, and better communication between governments and citizens. However, e-Government has not successfully implemented in developing countries, which is required to investigate key success and failure factors of e-Government projects as well as their causes. Therefore, this study aimed to determine critical factors that would positively impact both e-Government Processes and Benefits. This study developed an amended research model by combining Heeks` gap model and DeLone and McLean IS Success model, and considered Cambodian environment. Data were collected from 216 respondents including government officers and citizens who were interested in Cambodia`s e-Government. The research findings indicate that Technology Quality, Management Systems and Structures, and Staffing and Skills affect the benefits of e-Government project through e-Government Processes. However, Information Quality has no influence on the benefits of e-Government. In final, this study gives some guides of how to successfully implement e-Government project in Cambodia.