The experiment on Guinea pigs showed that allergic alveolitis (AA) was accompanied by disturbance of prooxidant and antioxidant systems’ functional condition. In experimental allergic alveolitis the dienic conjugates and malonic dialdehyde contents increase, and the activity of catalase, peroxidase and ceruloplasmin decreases in mesenterial lymph nodes. It was revealed the antioxidant correcting action upon the indicated indices in case of allergic alveolitis.