Cores J-3-RGA, J-11-RGA (south and central part of the Japan Sea) were studied for £_18O, palynological analyses, determination of carbonate and organic carbon content in sediments and dating by AMS methods. New AMS data on the J-11 core helped to identify the age of A-Tn volcanic ash as 25 thousands years. The Synthesis of the obtained data and the data provided by other cores taken in the Japan Sea reveal the detailed carbonate stratigraphy of Japan Sea sediments for the last 25 Ky formed in the course of the paleoceonographic ecolution of the basin. The carbonate horizons (CH) 1, 2, 3, are the result of the last glaciation event; they are related to the sea level regression and the semireduction condition of the bottom. The CH 4 and CH 7 were accumulated in Holocene sediments, and they are related to insufficient changes in the Japan Sea environment.