In a laboratory experiment was studied the influence of dimoxystrobin – the active substance of the fungicide Pictor on the nitrification activity and microbiocenosis of leached chernozem. It is shown that high concentrations of dimoxystrobin had no effect on microbial count of the soil, at first nitrification activity was inhibited and than stimulated by dimoxystrobin. The concentration of the dimoxystrobin in the soil at the level of 0.05 mg/kg was recognized as threshold by the effect on the nitrification process. The use of fungicides based on dimoxystrobin at maximum recommended rate of application will not lead to a breach of self-purification processes of chernozem in real soil and cli-matic conditions of Ukraine.