Abstract <p>The paper presents the results of structural-density modeling along a profile crossing structures in the southern part of the South Tatar Basin, located in the Tatar Strait in the northern Sea of Japan. The purpose of the modeling was to study the features of the deep structure and compare them with a previously studied area in the central part of the basin. In addition, the depths of the upper and lower edges of magnetized objects were calculated using the tangent method. As a result of the conducted research, a structural-density section of the crust was obtained, where the block structure of the basement was revealed, the differentiation of the composition of which is associated with the formation processes. Calculation of the depth of the edges of magnetically active bodies showed that they are confined to the upper crust, localized mainly in fault zones and volcanic structures. In the central part of the section, altered continental crust with signs of basification and volcanism was revealed.</p>