Copper is a life essential element. However, in excess it can be destructive to metabolism of microbial, plant, animal and human cells. Thus, an understanding of all conditions associated with the effect produced by copper on natural environment is vital. The purpose of the present study has been to evaluate the effect of soil contamination with copper on the activity of dehydrogenases, catalase and urease as well as to determine the tolerance of these enzymes to excessive amounts of copper in soil. The variable factors of the experiment consisted of: 1) soil type: loamy sand and sandy loam; 2) copper pollution rate in mg kg-1 d.m. of soil: 0, 150, 450; 3) soil use: unseeded and seeded soil; 4) crop species: barley, spring oilseed rape and yellow lupine; 5) dates of enzymatic analyses: 25 and 50 day. The results have revealed that copper pollution, within the rates of 150 to 450 mg kg-1 d.m. of soil, significantly inhibits the activity of dehydrogeanses, urease and catalase, with catalase being the most tolerant to excessive copper, unlike dehydrogeneases, which were the most sensitive enzymes. Urease was found to be intermediate in the response to copper. Dehydrogenases, urease and catalase are the least tolerant to the inhibitory effect of copper in soil under spring oilseed rape, being the most tolerant to the pollution in soil under oats. Copper produces stronger inhibitory effect on soil enzymes in unseeded than in seeded soil. The negative effect of excess copper in soil persists and, instead of diminishing, the longer copper remains in soil, the stronger effect it yields. Dehydrognases and catalase are less tolerant to copper in sandy loam than in loamy sand, unlike urease, which was more tolerant to the pollutant in loamy sand than in sandy loam. Tolerance of plants to soil contamination with copper is a species-specific trait. Among the tested crops, yellow lupine was the least tolerant whereas spring oilseed rape was the most tolerant to copper contamination.