For semigumid and semigumid-semiarid highlands of East Sayan we first characterized: one alliance, four associations, two subassociation, two variants relating to the class of ecological-floristic classification. At the upper boundary of the forest is dominated by larch woodlands (ass. Carici iljinii–Laricetum sibiricae ass. nova hoc loco). Association presented two variants: Hansenia mongholica and Empetrum nigrum. Variant Hansenia mongholica distinguished by good drainage conditions of habitats. Flat bottoms mountain hollows subgoltsy altitudinal belt and the upper part of the forest belt of alpine meadows occupied by swamped alpine meadows (асс. Cardamino pratensis–Caricetum stenocarpae ass. nova hoc loco). Yernik tundras (ass. Cladonio stellaris–Betuletum rotundifoliae ass. nov. prov.) are characteristic of subgoltsy altitudinal belt. Lichen tundras (асс. Carici ledebourianae–Cladonietum stellaris ass. nova hoc loco) typical for goltsy and subgoltsy altitudinal belts. They are represented by two subassociations nova hoc loco: typicum and empetretosum nigri. Habitat subassociation typicum wetter. We propose a new alliance Cardamino pratensis–Caricion stenocarpae all. nov. prov., which attributed to the order Violo altaicae–Festucetalia krylovianae and class Juncetea trifidi. Alliance characterizes swampy alpine meadows and meadow-tundras Altai-Sayan mountain region.Key words: syntaxonomy, high mountain vegetation, tundra, alpine meadows, subgoltsy woodlands, East Sayan.