Detailed studies of morphology and dynamics of the coasts of the contact zone of temperate and subarctic seas are considered on the example of Sakhalin Island-the contact zone between the subarctic Sea of Okhotsk and temperate Sea of Japan. The modern geomorphological structure of the Sakhalin coast is the result of a long and complex interaction of endogenous and exogenous processes of relief formation. This has determined the use of a wide range of methods to analyse the geomorphological structure of the tyerritor.