The results from studying the biota of soil cover in the influence zone of the aluminum smelters in the cities of Shelekhov and Bratsk (East Siberia) are presented. The study revealed the inhibiting effect of technogenic emissions on the main taxonomic groups of soil microorganisms. The weakest tolerance to the foreground pollutants was shown by the microbiota in the influence zone of the Bratsk aluminum smelter. It has been ascertained that the majority of the soil types under investigation have not reached the toxicity threshold.