Recently, beta-glucan has been postulated to modulate antioxidant enzyme activity (superoxide dismutase-SOD) as well as to inhibit lipid peroxidation in studies concerning rats or rabbits. There are very few reports on antioxidant effect of beta-glucan in the human blood. The study was aimed to estimate influence of Vita Glucan (VG) on SOD and catalase (CAT) activities as well as on total antioxidant power measured as ferric reducing activity and ascorbate concentration (FRASC) in the human blood in vitro. SOD activities were measured according to Fridovich's method, CAT activity by Aebi's and FRASC value by Benzi's one. Results of this study have shown that Vita Glucan at concentrations 42.5, 85, 170, and 340 mg x 100 mL(-1) increased markedly activities of antioxidant enzymes and FRASC values in human red blood cells hemolysates.