The distance education has been considerable development in China, its important to provide an efficient tool for online examination in internet or local area network. This paper analyzed the development of distance education and online examination system in recent years, and designed a online examination system. The author proposed the data flow, function modules, and the interface to other systems. In order to ensure the fairness and authority, the data store security and data transfer security has been studied .Finally, the authors introduce the system application. The system provides quality exam to students everywhere at a time and place that is flexible and accessible.