Аннотация:Urban soils differing in the intensity of anthropogenic loads in them were studied in several largest (Krasnodar), large (Sochi, Simferopol), and moderately large (Maikop) cities of southern Russia. The obtained data on the diversity of bacterial complexes in these soils suggest that in the urban soils with the high anthropogenic load (Sochi, Simferopol, Krasnodar), a considerable transformation of natural bacterial complexes takes place with a sharp increase in representation of Enterobacteriaceae. Along with microorganisms indicative of the sanitary state of urban soils (E. coli, En. faecalis), the soils also contain bacteria belonging to Klebsiella, Enterobacter, Citrobacter, and Serratia genera; some of their species may cause intestinal and allergic diseases. In the urban soil of Sochi, the spores of sulfite-reducing Clostridia, including Clostridium perfringens have been found. In the urban soil of Maikop with the lowest population density among the studied cities, changes in the structure of natural bacterial complexes are virtually absent. The abundances of sanitary-indicative microorganisms (E. coli and Enterococcus faecalis) enterococci) in urban soils of all the studied cities, except for Maikop, exceeded the normative value for sanitary-safe clean soils (<10 CFU/g soil).