In this article I attempt to summarize the change of the National Course of Study, mainly in the philosophical ideas since World War II. In 1947 when Japanese "New Education" started, they used the word "subjects" or subject contents not "curriculum". This is the result of the Japanese educationists not being able to go out of the Japanese tradition of educational ideas. However, in 1951 they agreed to use the word "curriculum" formally in the governmental documents. As a result, all of the Japanese schools developed two areas, that is, subject area and extra-curricula area. In 1958 the Ministry of Education (Monbusho) lauched National Course of Study of each school stage separately.And Monbusho could make their position stronger than before to the local educational authorities, in addition to the minimum of essencials of the content. In the revision of 1968, Monbusho changed the National Course of Study from the minimum to the standard or average. They recommended to the schools to construct their own curriculum in reference to the National Course of Study. But most Japanese schools did not want to change so much. In 1977 and 1988 Monbusho expected the schools to be more active in building their curricula creatively, while their attitude became more flexible and more open. Therefore, the present National Course of Study has not been very rigid, but ideologically it has still forced schools to show their loyalty and conformity to the nation. However, the long range of the revisional history of the National Course of Study shows the change from the strong power of the government to the flexible attitude of it.