Occurrence of soil micromycetes was investigated in soils at four localities in floodplain forests with Salix (S1-S4) and at four localities in floodplain forests with Populus (P1-P4) in the vicinity of Gabcikovo. The age category of forests were from 10 to 40 years. Thirty-one genera of microscopic fungi were determined from Fluvi - cutric Gleysol and Eutric Fluvisol (FAO). The most frequent genera are: Penicillium, Trichoderma, Aspergillus, Aureobasidium, Verticillium, Humicola.