The objective of this study was to determine the alleviating effect of cellulose on the biochemical properties of soil contaminated with nickel. Soil samples were contaminated with nickel chloride, and were fertilized with ammonium sulphate and cellulose. The experiment was carried out for 120 days, at a constant temperature and moisture content. The activity of soil enzymes (dehydrogenases, urease, acid phosphatase, alkaline phosphatase, arylsulphatase, ß-gluosidase and catalase) was determined on the day the experiment was established, and on days 15, 30, 60, 90 and 120 of the experimental period. It was found that soil contamination with nickel had a negative impact on the activity of soil enzymes. The sensitivity of the analyzed enzymes to this heavy metal may be presented in the form of the following series: urease > dehydrogenases > alkaline phosphatase > acid phosphatase > catalase > arylsulphatase > ß-glucosidase. The adverse effect of nickel on the activity of soil enzymes can be alleviated by soil enrichment with cellulose accompanied by fertilization with ammonium sulphate. The activity of the tested soil enzymes was subject to periodic fluctuations in samples incubated at a constant temperature and under constant moisture conditions.