Chernevaya taiga is a unique highly productive boreal ecosystem of Western Siberia. The composition of cultivated micromycetes in the soils of the chernevaya taiga (Novosibirsk and Tomsk Regions) was studied in comparison with the soils of oligotrophic pine forests. 39 species of micromycetes were identified, mainly from the Ascomycota division. 29 species of microscopic fungi were identified in the soils of the chernevaya taiga, while 18 species of micromycetes were recorded in the reference soils of pine forests. The species Cephalotrichum mi-crosporum, C. nanum, Cordyceps farinosa, Penicillium dierckxii, P. purpurescens, and Trichoderma viride were recorded only in the soils of the chernevaya taiga. The change in the number, biomass and species composition of soil micromycetes depending on the trophicity of the soil is shown. The number of micromycetes ranges from 2 to 34 thousand CFU/g (using the inoculation method) and from 3.2 to 26.2 million CFU/g (using the direct mi-croscopy method). The biomass of microscopic fungi in soil samples from the chernevaya taiga ranges from 0.082 to 0.965 mg/g soil, while in the reference soils this indicator was significantly lower and ranged from 0.07 to 0.117 mg/g. It has been shown experimentally that most of the strains isolated from the soils of the chernevaya taiga take part in the decomposition of cellulose and polysaccharides, and a relatively small proportion of species can be considered as lignin destructors.