[in Russian with English abstract: ] The paper provides an ecological and substrate analysis of lichens of the State Nature Reserve «Zavolzhsky» (Chuvash Republic). In the specified reserve 134 species of lichens were found. The ecological and substrate analysis showed that lichens were found on 20 substrates: on the bark of Populus tremula, Tilia cordata, Quercus robur, Acer platanoides, Betula pubescens, Padus avium, Sorbus aucuparia, Frangula alnus, Salix cinerea, S. pentandra, Alnus glutinosa, on the bark and branches of Pinus sylvestris, Picea abies, Abies sibirica, Betula pendula, on soil, on a dead organic substrate, on an anthropogenic substrate (on slate, concrete, wheel rubber). 6 main and 4 intermediate ecological groups of lichens were revealed: 1) epiphytic, growing on the bark of trees and shrubs; 2) epixylic, living on decaying wood; 3) epigeidic (ground lichens); 4) epibriophytic, living on mosses; 5) epiphytic-epixylic, growing on the bark of trees and a dead organic substrate; 6) epixylic-epigeidic, living on a dead organic substrate and soil; 7) lichens growing on the bark of trees and anthropogenic substrate; 8) epiphytic-epigeidic, growing on tree bark and soil surface 9) multisubstrate lichens that live on different substrates; 10) lichens of anthropogenic substrate. The largest number of lichens (61,2%) belong to epiphytic, 16,5% – to epiphytic-epixylic, 5,2% – to epixylic-epigeidic, 4,5% – to epigeidic, 3,7% – to epixylic, 2,3% – to epibriophytic, 0,7% – to multisubstrate lichens, 0,7% – to epiphytic-epigeidic. 3 species of lichens were found (2,3%) on the anthropogenic substrate. Epiphytic lichens were found on 15 forophytes. The largest number of taxa (40 species) were found on Pinus sylvestris’s bark, 35 species – on Populus tremula’s bark, 33 species – on Betula pendula’s bark. 56 species of lichens were found on only one forophyte. The analysis of the confinement to phorophyte showed that the highest level of similarity in the species composition of lichens was found between Padus avium and Frangula alnus – 50%, Pinus sylvestris and Picea abies – 49%, Populus tremula and Sorbus aucuparia – 44%, Tilia cordata and Acer platanoides – 41%, Salix cinerea and S. pentandra – 37%. Keywords: lichen; state nature reserve «Zavolzhsky»; specially protected natural area; ecological and substrate analysis; ecological groups; substrate confinement; phorophytes; lichen similarity level; Chuvash Zavolzhye; Chuvash Republic.