Soils are the memory of ecosystems and landscapes because of the ability to preserve the information about the environmental conditions of their formation, they can be used for establishing the principles of environmental evolution. Morphological characteristics, peculiarities of composition and properties of the Middle Pleistocene paleosol and its components formed at the Brunes-Matuyama boundary within the mountain-forest zone of the Southern Urals are considered in this publication. Comparison of the characteristics of paleosols with modern soils diagnose it as an analogous of leached Chernozem. This is evidenced by a set of morphological characteristicz of corresponding distinct horizons, the redistribution of silty particles along the profile of paleosol, the predominance of humic acids over fulvic acids in humus composition, as well as the quantitative predominance of carbon atoms over hydrogen in humic acids. Consequently, it can be concluded that the formation of paleosol in the studied period of paleogeographical Middle Pleistocene history occurred under conditions close to modern ones, corresponding to the subzone of the Northern forest-steppe.