Presented are the results from studying and mapping the soil cover in the Tunkinskaya depression (Southwestern Cisbaikalia). According to the principles of a substantive-genetic classification, we have performed the depression’s soil systematics and diagnostics. We identified soils referring to 4 soil formation trunks, 14 divisions and 56 types. A detailed study of their morphological and physicochemical properties revealed new classification units at the subtype level, reflecting the local peculiarities of soil formation. Taking into consideration the empirically detected regularities in soil successional changes across space, we determined the combinations of differentiation mechanisms for soil cover that operated within the main morphological elements of the Tunkinskaya depression (surrounding mountains, inclined and alluvial piedmont plains, lake-bog lowlands, and sand ouval-massifs). The concept of the soil cover structure and the levels of its organization was used in compiling the 1:200 000 soil cover map for the study area. The transition from separate soil profiles to soil areas is done by interpolating the soil sampling points through the use of the landscape indication method. For this purpose we used the SRTM Digital Elevation Models, the 3D relief model, different-scale and different-time geological, topographic and economic maps as well as Earth remote sensing maps.Keywords: soils, soil cover structure, soil cover differentiation factors, Southwestern Cisbaikalia.