Some species are so sensitive to environmental changes that may serve as indicators, which defines their significance for a complex evaluation of ecosystem condition on the territory under study. The current research shows that separate species of dragon-flies (and the reofile species in particular) are very sensitive to pollution and can serve as the indicators of environment. The research was conducted mainly in the area around the cities of Novokuznetsk, Mezhdurechensk, Osynniky, Kiselevsk, Prokopyevsk and Tashtagol, where the Tom-river is contaminated with pollutants from industrial sewage. The authors made an attempt to analyze the odonatocomplexes of the water sources of the Tom’ River basin (the Tom, the Kondoma, the Aba, The Mrass-su) and register the chemical structure of the water. The results showed that the general odontocomplex of the Tom’ River basin consists of 6 kinds of rheophils. However, downstream from large industrial centers, there is a sharp decline in the number of species, almost to the point of complete disappearance at some rivers, which clearly correlates with the degree of water pollution.