Classification of plant communities of any region is the scientific basis for evaluation biodiversity, organization of its protection and rational use. Different methods are used to classify vegetation. At present the floristic method is widely used.

The floristic classification of mire vegetation of Karelia had been established on the basis of 5000 reveles. It includes 36 associations, which refer to 12 alliances, 9 orders and 5 classes. We pointed from 2 to 8 subassociations in 14 associations.

Many associations have been delimited in comparison with descriptions in classifications of mires of Northern Europe (Dierssen, 1982) and mires of the North West of Russia (Boch, Smagin, 1993). 10 new associations have been formed. They need valid publications. For example in the class Alnetea glutinosae Br.-Bl. et Tx.43 in the alliance Crepido paludosae-Piceenion abietis Solometch 94 we have established two associations: Calamagrostio canescentis-Piceetum abies ass.nova and Calamagrostio canestencis-Pinetum sylvestris ass.nova. They include wood - herb eutrophic communities. Association Caricetum lasiocarpae Osvald 23 is delimited, it includes only grass and grass-bryales communities with Carex lasiocarpa as dominant. Communities of Carex lasiocarpa having full sphagnum layer with different species are included into ass. Carici lasiocarpae - Sphagnetum fallacis Waren 26 em.Rybnicek 84. We had the same approach to divide associations Caricetum rostratae Osvald 23 em. Dierssen 82 and Caricetum limosae Osvald 23 em. Dierssen 82. Two associations Molinio caerulei - Sphagnetum papillosi and Molinio caerulei - Sphagnetum warnstorfii were singled out as specific for Fennoscandia. The following associations can be distinguished as rare for Karelia: Alnetum glutinosae -Sphagnosum Schwickerath 44, Caricetum diandrae Jonas 32 em. Oberd. 57, Rhynchosporetum fuscae W.Braun 68, Trichophoro- Schoenetum ferruginei (Booberg 30) Gors 64. Some subassociations in other associations are also rare.