In model systems the effects of organic pollutants on the antioxidant status of Elodea sp. were studied. It was showed the changes of Elodea antioxidant activity during the increasing concentrations of urea (from 100 to 1000 mg/l) and monophenol (0,1 to 10 mg/l). The effects of various types of phenolic compounds (monophenol, hydroquinone, catechol and resorcin) on the antioxidant activity Elodea were compared.