Six zonal and subzonal ornithogeographical boundaries were identified in East Fennoscandia and the north of the Russian plain by analysing bird geographical ranges. The boundaries are relatively close to the lines of total temperatures above 10°C over the growing season (with an interval of 200-300°C). The most important meridional limits of bird distribution coincide with the boundaries of the Scandinavian Mountains, East Fennoscandia, Timan-Pechora province and the Urals. The taiga in East Fennoscandia and north of the Russian plain has been divided into 12 ornithogeographical sectors. The taiga sectors are described. Differences between them are substantiated by data on the bird range asymmetry, differential species set, and sequence of the local fauna composition. Proposals on revision of the zoogeographical zoning units are put forward.