The distribution patterns of birds in East Fennoscandia and the north of the Russian plain (over 270 species in total) were analysed, and a revised classification of faunistic bird groups was proposed for the west of Eurasian laiga. The following groups and subgroups of species were identified: of north- and mid-taiga, hypoarctic, North Atlantic, Arctic, Atlantic boreal formations, forest palearctic fauna, European broad-leaved and Far Eastern conifer-broad-leaved forests, Mediterranean, plurizonal. The birds of Atlantic boreal formations are included as a subgroup in the taiga complex. The subgroup of North Atlantic species belongs to the Arctic fauna. The scope and composition of faunistic groups as applied to East Fennoscandian regions are described.