Oksky Biosphere Nature Reserve is situated in the Central part of European Russia, in the southern part of Meshchera Lowland, 54°40'-55°00' – 40°35'-41°01', 80–160 m alt. Its territory includes 557 km2 and also neigboring area of 214 km2 is partly protected. The main type of vegetation is pine forests on relatively poor sandy soils and secondary Betula forests, appearing after extensive clearcuttings in the early and middle XX centure. A considerably part of the reserve is flooded in spring to early summer for 3-9 weeks. In flood valley old oak forests occur, covering 4.6% of the territory of the reserve. The bryophyte flora includes 154 species of mosses and 27 species of hepatics. An annotated list and discussion on general bryophyte complexes are given. In the list the occurence of species is abbreviated as follow: C – common; S – sporadic; R – rare; U – unique.