After the 1995 Kobe earthquake, review of the intensity level of design earthquake motion has been often discussed. In order to provide the basic data for the discussion, this paper examines the occurrence rate of the destructive ground motion based on the case histories of damage earthquakes in Japan. The isoseismal maps of the earthquakes which caused the destructive motion of the J.M.A. seismic intensity 6 or 7 are collected. The characteristics of the earthquakes and the effect of surface geology on the isoseismal maps are discussed to derive the factors which cause the destructive motion.
