The antioxidant properties of alcohol solutions of mangiferin were studied. The antioxidant activity in linoleic acid/water emulsion system, determined by the thiobarbituric acid reactive substances (TBARS), was higher at 37°C – 72.0%, and by inhibiting conjugated dienes formation – 70.4%. At 80°C the antioxidant activity at the highest concentration was less efficient: 67.2 % for conjugated dienes and 69.1% for TBARS. Mangiferin inhibited the hydroxyl radicals by 84.3% at 37°C and 79.8% at 80°C, as it showed a higher antioxidant activity than quercetine. The IC50 concentration for the inhibition of OH· at 37°C was lower than that at 80°C – 0.88 µg/ml and 1.81 µg/ml, respectively. Mangiferin chelated Fe3+ in the solution. The inhibiting effect of mangiferin with regard to the xanthine oxidase activity was weaker – 71.4%, as IC50 concentration for the reduction of nitroblue tetrazolium was 14.17 µg/ml.