[in Russian with English abstract: ] The article presentes data analysis of lichens of the Baunt District of the Republic of Buryatia. This region is characterized by a significant area, geomorphological heterogeneity of the surface, an extreme climate and interesting local ecosystems. Local lichens belong to the mountain-boreal biota, since the area is located in the boreal zone of the Hol-arctic. Lichen flora represents different phytogeographical patterns with residual and consistent interchange of vegetation formations. The most lichen species are concentrated in the areas of rock outcrops, especially carbonate outcrops. In extreme conditions, epiphytic lichens grow in shelters on various substrates in a medium-scale ecosystem: inside rocks, near thermal springs, in mountain forest valleys or on slopes exposed to the sun. The valleys that were not glaciated during the Quaternary period serve as shelters for the rare species of tropical and non-moral origin. As a result of the conducted research, several rare and vulnerable species of lichens have been identified, listed in the Red Books of various ranks.