In the present work, our goal was to establish the resistance of microscopic prokaryotes and eukaryotes on three sulfonylurea substances in soil or prepared as suspensions. Based on obtained data, different kind of bacteria, actinomycetes, filamentous fungi and algae were observed. Among the species of bacteria, we mention the Bacillus megaterium. As actinomycetes, there are the following: Streptomyces griseus, Streptomyces albus, Streptomyces aureus. Penicillium and Rhizopus are mold species. Coccomyxa lacustris has been taken out from the Green algae group.