Abstract: Although the meaning of the concept “Japanese state form”is quite different before and after World War II, it can be reflected from the status and role of the emperor in the constitutional system.Before the Second World War, the Japanese state form was an important concept in the field of law and politics. The legal basis and connotation established by it were concentratedly embodied in the provisions of the Meiji Constitution concerning the emperors supremacy of state power and other theocracy status.After World War Ⅱ, the Japanese government insisted on the interpretation of the so-called “post-war state form unchanged”,and bound the concept of the Japanese state form with the symbolic emperor system established by the post-war constitution, resulting in the creation of the symbolic image of the emperor directly related to the changes in the so-called post-war state form.By examining the status and role of the emperor in the pre-war and post-war constitutional systems, we can know that the relationship between the role of the emperor in the political life of the country and the Japanese state form in modern times is like two sides of the same coin. They are closely related to each other and cannot be separated.

Key words: Japanese emperor, Japanese state form, Meiji Constitution, constitution of Japan