The automotive industry is the main source of environmental pollution with platinum group metals, which increases the concentration of platinum in road dust, soil, and plants. This can lead to the achievement of toxic levels of this metal in the environment, and consequently, an imbalance of the ecosystem, a reduction in the microbial population, and a decrease in soil fertility. The effects of platinum on the activity of oxidoreductases of ordinary chernozem have been studied: the activity of catalase and dehydrogenase. Platinum was introduced into the soil in the form of chloride. Platinum concentrations were studied – 0.01; 0.1; 1; 10 and 100 mg/kg. The change in the indicators of ordinary chernozem was assessed 10, 30 and 90 days after contamination. The absence of a stimulating effect of platinum chloride on catalase activity, the effect of hormesis on the activity of dehydrogenases of ordinary chernozem has been established. The dependence of the degree of decrease in indicators on the concentration of the pollutant in the soil and the time from the moment of contamination is shown. The study shows the negative effect of even a small concentration (0.1 mg/kg) of platinum chloride on the enzymatic activity of the soil. Early diagnosis of the degree of soil contamination with platinum compounds can be successfully used to promptly assess their impact on soil condition and prevent possible negative consequences.