A landscape-ecological analysis is given of the structure of the soil mesopopulation in steppe geosystems of the Prebaikalia. The paper considers regularities of changes in quantitative characteristics of invertebrate communities under the influence of natural and anthropogenic factors, as well as peculiarities of distribution of taxonomic diversity at the landscape basis. The main trend of changes in taxonomic diversity of pedobionts communities is a decrease in the species number in the gradient of an increase of climate aridity, and strengthening of the hypothermal character and anthropogenic pressure.