This paper describes the development of the theory of peace education after the Second World War, and analyses it from a sociological viewpoint. Firstly it describes historical development of the theory of peace education. The ideal of pacifism in the theory of peace education has been traced to the Constitution of Japan and the Fundamental Law of Education, which were established just after the last and lost war. The memory of the last war experience was lessened during the period of high growth of Japanese economy, but peace education for passing on the war experience began to develop in the early 1970s. The session on ""peace education"" in the Japan Society for the Study of Education was set up in 1976, it meant that the importance of peace education was recognized at the academic level. After 1990, the theory of peace education in a broad sense has studied not only structural violence but also human rights and international understanding from a comprehensive viewpoint. This paper sociologically analyses the relations of social factors which have influenced the development of the theory of peace education. This research shows that constructing of peace educational theory have been under the influence of social factors as follow; the lost war experience, political party confrontation after 1955, documents issued by the UN or the UNESCO, mass media, overseas theory of peace education, and peace studies. Japanese theory of peace education performed a social function to explain theoretically the necessity for keeping and freshening of the collective memory of the last war. It has recognized the importance to train the affection, recognition and behavior of children towards peace building. Japanese theory of peace education has made importance of historical method, but now it needs to apply geographical method more often and social studies which socialize children towards the conflict resolution and constructing a peaceful world. It is necessary to systematize the theory of peace education and to promote peace ed