The features of slope failure at the sea cliff of the Muroto peninsula, Shikoku district, were analyzed by the aerial photo interpretation and the field investigations. Some essential characteristics of the slope failure became clear. Those slope failures at the sea cliff often occurred at the time of great earthquake. While the slopes of terraces, which are covered by forest keep being stable, though abandoned terraces which had been used for cultivation will often collapse on the occasion of the heavy rainfall because of the lack of maintenances. As for the slopes which consist mainly of unconsolidated terrace deposits, the cycle of the slope failure is about 20 years. The erosion rate of basement rock, Shimanto groups, is about 5. 6cm/year.