This paper presents an overview of the development of tephrochronology in Japan, and discusses several problems regarding the Japanese Quaternary. The impact of developments in such subjects as soil science, archaeology, radiometric dating and many other disciplines of Quaternary research has stimulated the tephrochronology in studies of earlier periods. However, recent advances seem more closely related to indigenous factors. Since the early 1970's, systematization of tephrochronology and fundamental characterizations for the identification of widespread tephras, occuring in and around the Japanese Islands, have initiated revision and refinement of regional stratigraphies, revolutionary studies of tephra for determining the nature and effects of explosive eruptions, and new applications to several aspects of Quaternary studies. A compilation of tephra catalogue for the Japan region provides fundamental data for correlations on land and in sea and for determining the recurrence period of cataclysmic explosive volcanism.