1. Marine terraces along the coast of Hokkaido are one of the most significant morphological features. Nobody has, however, made any synthetic investigation of the fluctuations of the altitudes of these terraces, and the significance and the ages of the terraces. The coast is the most sensitive to the change of the base level of erosion, and the altitude of the former shore line indicates the amount of the vertical displacement by the crustal movement at shore. From such a point of view the anther has discussed the features of the crustal movement in the latest geologic age, the relation to the tectonic movement in Hokkaido and the chronology of the terrace surface forming periods.<br> 2. The investigated area is Hokkaido proper, one of the geotectonic units. The anther has selected two terraces, called Chikubetsu (C) and Tomamae (T) along the coast of Haboro district in the northwestern part of Hokkaido. The altitudes of these terraces are 70-50 meters and 60-30 meters above the sea level respectively. Along the coast of the northern part of the Kitami Mountainland, the northeastern of Hokkaido, the altitudes of the two former shore lines are uniform, namely one of the C-shore line is 80 meters and of the T-shore line is 40 meters above the sea level. Considering these values as the standard ones, the auther has made three fluctuation curves of the altitudes of the former shore lines, from the end of the formation of the C-terrace surface till the beginning of the T-terrace formation, from the end of the formation of the T-terrace surface till today, and from the end of the C-terrace surface formation till today.<br> 3. Morphological features of Hokkaido have been formed by the linking of the Kuril arc against the Ezo arc. The morphogenetic activity of the Kuril arc began in the Miocene. The auther has estimated a shear line running from east to west in the middle of Hokkaido, the inner zone of the Kuril arc. During the Neogene the mass of Hokkaido dislocated wholly to the west, and that the south half of this mass advanced strongly along the shear line. After this movement the recumbent folds were formed in the Ishikari Coal Field and at the same time the folds arranged en echelon were formed in the inner zone of the Kuril arc. Moreover, another related features in the land and submarine reliefs are found: i) A branch of the Japan trench south of Tomakomai extends northward from the Ishikari depression to a follow between the continental shelf west of Teshio and the Musashi bank. ii) The westside slope of the continental shelf surrounding the Cape Erimo continues northward to the Asahikawa depression. iii) The submarine valley south of Kushiro continues northward to the continental slope north of Abashiri or to the estimated fault line of Notoro via the Kutcharo caldera. These morphological structure lines run almost in parallel to each other trending to the Ezo arc. The coasts having the large deviations of the vertical displacement of the former shore lines correspond exactly to the parts running the just mentioned structure lines. Namely the activity of the Kuril arc continued rather actively during the latest geologic age.<br> 4. According to the pollen analytical studies of the terrace deposits, a rather cold climate is estimated in the T-surface forming period. As a moler tooth of Mammontius primigenius has been found in the deposit of T-terrace near the Cape Erimo, Prof. M. Minato, University of Hokkaido, has correlated this deposit to the Würm ice-age. The temperature in the C-surface forming period is estimated some degrees lower than the present, and also a period of a more cold climate is estimated in the boundary between the Paleo- and Neo-diluvium.