[In Russian with the following English summary:] Despite the large number of studies devoted to the analysis of the genesis and geography of spruce forests, species diversity of lichens of mature spruce forests still has not been the subject of a special study. The purpose of the research is to conduct taxonomic and ecological studies of lichen of mature spruce forests of Vitebsk Region, on the example 2 of protected areas: National Park «Braslav Lakes» and Reserve «Krasny Bor». Material and methods. Collection of lichen in mature spruce forest aged 8 to 120 years was carried out by conventional methods. The age of spruce forest was determined with the help of forest taxation characteristics. Species composition of lichen in mature spruce forests was studied in 32 localities, in the area of 109 hectares. Lichens on the protected areas were collected in 7 types of spruce forests. Findings and their discussion. The species composition of lichens and closely related fungi of mature spruce forest contains 122 species, including 117 species of lichens, and 4 non-lichenized saprobic fungi and one lichenfilous species. For the first time in Belarus Biatora epixanthoides lichen was recorded. For spruce forests of the Republic for the first time 17 new species of lichens and closely related fungi were identified, and in spruce forests of Vitebsk Region – 26 species. Thus, for the first time for the spruceforests of Vitebsk Region 44 new species of lichens and closely related fungi were identified. The biggest number of species in mature spruce forests was noted in spruce bilberry – 57 species. On tree bark the greatest number of species was found among 8 substrates – 91 species. Conclusion. The obtained data clarify and complement the diversity of lichen in spruce forests of Belarus. As our initial studies showed lichen of spruce forest requires further study. Key words: lichen, biodiversity, mature spruce forests, Vitebsk Region, Belarus.