Up to the present, twelve research papers have been published to estimate the earthquake danger in the vicinity of Japan. Unfortunately, however, the estimated danger from these researches do not coincide with each other but scatter widely depending on the various conditions they utilized.It is naturally required that we arrive at a generally agree-able view which is useful for practical aseismatic design purposes.

An endeavour was made for the purpose of defining the regional coefficients of earthquakes in the whole vicinity of Japan. The final solution thus obtained is shown in Fig. 6 in which regional coefficients reflecting only past seismicity are exhibited.