The aim of the study was to determine the effect of soil contamination with Treflan 480 EC on the content of macroelements in spring rape and white mustard and the relations between the accumulation of macroelements and the soil enzymatic activity. Soil contamination with Treflan 480 EC in doses from 1.5 to 12 mm3 kg-1 of soil modified the chemical composition of spring rape and white mustard. Increasing doses of this herbicide caused a significant increase in the content of the examined macroelements in white mustard and spring rape. The application of Treflan 480 EC caused considerably greater changes in the content of macroelements in white mustard than in spring rape. The application of this herbicide had a particularly great effect on the increase in the content of nitrogen, sodium and magnesium in the above-ground parts of white mustard. In the soil contaminated with Treflan 480 EC, the content of nitrogen was correlated with the activity of urease and the content of phosphorus was correlated with the activity of acid and alkaline phosphatase. These correlations were negative for spring rape, while for white mustard they were generally positive.