The present school is faced with the crisis of school collapse and classroom collapse under a bureaucratic and authoritative atmosphere. The method to respect individual opinions and to discuss with open mind is needed. The study is to establish the system of SDR and to make it possible to express the wholesome and various ideas of members by using it. SDR is related with the interruption DB to stop up unsound messages. The result of this study shows that SDR is very helpful to make a culture of discussion in a school in the respect of enlarged chances for teachers and students to participate, active and open participation, changing of attitude in achieving group goal and formation of desirable culture of discussion.