Given the recent problem of climate change, nuclear power has become perhaps the world¡Çs most important energy source. In Japan, however, it is difficult to build new nuclear facilities. One of the reasons for such difficulty lies in problems in risk communication. In this study, a support method has been proposed to improve mutual understanding in risk communication. The authors paid especial attention at the learning effect of debating and the benefits of employing a debate support system. A laboratory experiment including 30 university students was conducted in order to evaluate the proposed method. Results showed that the use of the system could improve mutual understanding especially with respect to the factors of risk ¡Æreduction measures¡Ç and ¡Æaccident management¡Ç. In addition, it was found that using the system and debating from ¡Æopposite positions¡Ç could improve subjective mutual understanding; however, this practice showed no effectiveness in terms of improving objective mutual understanding.