Screening of phytotoxic properties of 5 micromycete strains were made concerning cultivated plants and weeds. All of the strains show phytotoxic activity of different levels. In particular, the cultural filtrates of Penicillium sp. 10-51 and Aspergillus niveus 2411 suppressed the growth of seeds of Galinsoga parviflora, Amaranthus retroflexus and Capsella bursa pastoris. The cultural filtrate of Ulocladium consortiale 960 suppressed the growth of Panicum capillare and Setaria viridis. The greatest phytotoxic activity was shown by the cultural filtrates of Myrothecium cinctum 903 and 910, on the one hand, both of them suppressed the growth of seeds of E. virgata completely, but, on the other hand, they did not take any effect on the seeds of radish.