Detailed field work was carried out at Okushiri Island and along the southwest coast of Hokkaido. Results clearly indicate that only a few residential areas were hit by a huge tsunami, with true heights reaching 10m. Southern Aonae was completely swept away by tsunami that came directly from the focal region immediately to the west. Coastal structures were effective in reducing tsunami hazard at many sites. The maximum flow velocity at northern Aonae was estimated as 10 to 18m/s (Tsutsumi et al., 1994), and such a high on-land velocity of tsunami near shore is probably due to the rapid shallowing of the deep sea near the epicentral region towards Okushiri Island.