The paper is devoted to ecological and biodiversity studies on basidiomycetes associated with common juniper (Juniperus communis) from subtaiga zone of Belarus as well as several taiga regions of the European part of Russia, namely, the Leningrad Region, the Republic of Karelia, the Komi Republic, the Arkhangelsk Region, the Murmansk Region. The taiga zone represents an ecological-coenotic optimum of common juniper and the widest spectrum of its fungal consorts is expected to be revealed. A total of 96 species of wood-inhabiting basidiomycetes, both from dead and living wood, were recorded in association with J. communis in the boreal regions of Belarus and the European part of Russia. These species belong to the Pucciniomycetes (Pucciniales, 3 species), Dacrymycetes (Dacrymycetales, 1 species), and Agaricomycetes (Agaricales, Atheliales, Auriculariales, Boletales, Cantharellales, Gloeophyllales, Gomphales, Hymenochaetales, Polyporales, Russulales, Thelephorales, Trechisporales, 92 species). An annotated species list is given, including an expanded substratum and ecology datasets. The ecological and geographical preferences of these fungi and the strength of their connection with juniper were analyzed by thermal map, clusterization, and Sankey diagram methods. The various types of wood decomposition by juniper-associated basidiomycetes were discussed. The global distribution pattern of the species was analyzed. It was concluded that the biota of basidiomycetes associated with juniper in Eastern European taiga forests is a heterogeneous and heterochronous formation, where it is possible to distinguish clearly a florogenetically ancient core of the species specialized on juniper, exhibiting in one or other way biotrophic properties, and several taiga sets of species (suites) connected with pine trees and their litter as well as with spruce-pine-leaved taiga mosaics and boreo-nemoral mosaics typical of the Northern Hemisphere.