The clavarioid fungi (Basidiomycota, «Aphyllophorales») in the tundra and taiga zones of Chu- kotka (Siberian north-east) have been studied for the first time. Typhula umbrina Remsberg is reported for the first time from Russia and Eurasia. Mycobiota of the Chukchian tundra is characterized by the highest diversity (37 species in 10 genera) of clavarioid fungi in Eurasian Arctic, on the other hand – the taiga (forest-tundra) mycobiota – the poor (43 species from 12 genera) if compared with the over forest-tundra’s regions. The mycobiota differs also significantly by its taxonomic composition, way of nourishment (trophic) and ecomorphological structures from other parts of Eurasian Arctic. About 27
% of species are new to tundra in Eurasia and all of them have a boreal or nemoral distribution. Also, high role of boreo-nemoral vascular plants were found for the flora of Chukotka, as a part of Beringia. The specificy of studied mycobiota in the scale of Eurasian Arctic are the greatest role of species on the dead leaves and dead wood, as well as total domination of species with simple fruitbodies (Clubtype life form) and predomination of the genus Typhula. This is typical for open, xero-cryophilic landscapes of Beringia where grasses of steppe-meadows and some taiga trees played an important role. Further investigation of mycobiota biodiversity and structure with regard to Arctic complexes of different fungal groups is a precondition for creating of Mycogeographycal Maps of Russia and worlds Arctic regions.