The paper provides information about lichens found on the territory of the state natural reserve Zavolzhsky, which is a specially protected natural area of the Chuvash Republic. It was established for the protection of the unique natural landscape, located on the territory of Cheboksary and Cheboksary District, as well as for rare and endangered animals, plants and other organisms from high anthropogenic activity. As a result of lichen investigations (20112016) 134 species belong to 59 genera from 31 families of lichen flora were recorded. It emphasizes a high environmental significance of this territory. The paper shows substrate and biotope confinement for each lichen species. The investigations were conducted in detail-route method using a GPS-navigator. In the paper the locations of rare lichen species are given according to the new quarterly network of the Cheboksary forestry. We examined the lichen diversity in 14 quarters of 3 forest districts: Pihtulynskoe, Severnoe, Sosnovskoe; lichen collections were carried out in 36 habitats. The habitat of rare and endangered lichen Lobaria pulmonaria was found on the territory of the reserve. This species is included to the Red Data Book of Russia. According to the results of the study we recommend to include 15 rare lichen species to the new edition of Red Data Book of the Chuvash Republic: Arthonia cinereoprunosa, Acrocordia gemmata, Bryoria implexa, Bryoria subcana, Bryoria nadvornikiana, Dimerella pineti, Lobaria pulmonaria, Mycobilimbia epixanthoides, Mycobilimbia carneoalbida, Mycobilimbia tetramera, Platismatia glauca, Usnea dasopoga, Usnea lapponica, Usnea subfloridana, Xanthomendoza ulophyllodes.