ABSTRACT. The activity of peroxidase (EC 1.11.1.21) and superoxide dismutase (EC 1.15.1.1) was studied in barley and bean seedlings with contrasting salt tolerance grown under extreme salinity conditions. According to our results, the change of peroxidase activity is adequate as the concentration of isolation sodium salts increases in the above-ground parts of barley and bean seedlings grown in water culture. It was found that the activity of SOD in the root system of both barley and bean seedlings was lower than in the shoot part. The activity of SOD in the root system of 7-day-old barley seedlings cultivated in water culture increased with the increasing concentration of chloride and sulfate salts (25-50mM). The subsequent increase in the concentration (75-100mM) resulted in reduced enzyme activity although exceeding the activity in control plants. The enzyme activity in barley seedlings grown in soil culture was weakened by the influence of salts. It should be noted that the linear nature of the increase in SOD activity in the root system of bean seedlings cultivated in water culture when the concentration of salts increases indicates a decrease in the amount of substrate in the root system. The study of enzyme activity in the root and shoot parts of barley and bean seedlings with contrasting salt tolerance grown in soil and water culture under extreme salinity, which allows determining the adequate or specific nature of peroxidase and superoxide dismutase reactions.