Abstract: With the continuous development of network technology, distance education has greatly advanced. At present, distance education is not restricted to the academic education but various vocational education as well. Meanwhile, distance education will make great progress in the future as the spread of lifelong education in our life. However, there is no key solution to the oral defense of graduation thesis which is the key link of the distance educational argument. After analyzing the problems in current distance educational argument, the author put up with a systematic solution via an entity modeling of the graduation process. What is more, in order to provide a powerful virtual network platform for educational argument, the author developed a system for distance educational argument based on the Flash Communication Services Technology. There are four different user roles designed for the system: student, teacher, spectator and manager. Different roles have different rights to use system services. Except for offering service to many users simultaneously, the system is equipped with function of video communication, voice communication, text chat, white board show, slide show eva luation and so on.