The issue on energy and environment is one of the most important issues to realize sustainable society in the future, and not only technological innovation on energy and environment but also various social knowledge and ability of total judgment is required in order to tackle the issues. In this study, therefore, an educational debate support system has been developed based on Web technology to learn the knowledge and to foster these abilities. The system can be easily introduced to actual lecture, and it has effective functions to support logical discussions by students and evaluation by teachers. And it was applied to two lectures in graduate school of energy science, Kyoto University, ¡ÈSocio-environmental energy science I¡É and ¡ÈSocio-environmental energy science II¡É in order to educate the students and to evaluate the developed system.