The paper presents the results of biodiversity assessment on the territories with different ecological conditions. The studies were carried out on the territories during the reforestation period after the anthropogenic load associated with deforestation, as test sites (PP) and forest biogeocenoses adjacent to deforestation and not affected by forestry activities - control (K). The research methods are indicated. The Jacquard and Stugren-Radulescu coefficients, as well as the Sorensen-Chekanovsky and Kulchinsky indices were used to assess the biodiversity. During the survey of the territories, 32 species of animals were found: 1 species belongs to the class of amphibians, 5 - reptiles, 13 - birds and 13 - mammals. The list of the faunal composition of the studied territories is given. As a result of the conducted studies it has been revealed that the qualitative and quantitative characteristics of the faunal composition directly depend on the derived type of forest, the method of deforestation and the environmental conditions prevailing on this territory. Of the territories considered, the greatest faunal diversity (19 species) was observed on the territories with 12-year-old-cut-down forest, with moderately moist soils and predominant floristic diversity. Based on the calculation of the indices and coefficients of similarity and difference, the similarity of the species faunal diversity has been revealed on the territories of mixed-grass and blue joint fellings as well as in the control areas of lingonberry pine. The difference from all the sample areas has been revealed in the meadowsweet felling (PP1) and the adjacent forest biogeocenosis - grass-marsh pine forest.