Higher, middle and Lower Terraces (Quaternary) have been distinguished in Yokohama Town, Aomori Prefecture. The Higher Terraces are subdivided into three terraces, H1,H2 and H3. They are distributed in hills. H1 and H2 deposites are composed of gravels of fan deposits. H3 deposits are composed of gravels, sands and mud of alluvial plain deposits. The Middle Terraces are subdivided into three terraces, M1, M1' and M2, and occupy almost all terraces in Yokohama Town. These deposits are composed of beach (sand with gravel) and fan (gravel) deposits. The Lower Terraces are subdivided into two terraces, L1 and L2. The L1 Terrace is distributed in limited area along coast and thought to be composed of beach deposits. The L2 Terrace is distributed in limited area along river and composed of braided stream deposits.