This experiment was carried out to investigate the effects of dietary vitamin C and E on carcass characteristics of Hanwoo steers. Thirty seven Hanwoo steers were randomly assigned to one of four treatments. The four treatments were control(vitamin E 20 IU/kg feed), vitamin C(vitamin C 0.1%/kg feed and vitamin E 20 IU/kg feed), vitamin E(vitamin E 220 IU/kg feed) and vitamin C plus E(vitamin C 0.1%/kg feed and vitamin E 220 IU/kg feed). Hanwoo steers were fed experimental diets for 3 months of the last finishing period. Animals fed the diet containing vitamin C plus E had higher(P<0.05) yield grade than those fed the other diets but quality grade was not different between animals fed the control diet and vitamin-supplemented diets. Proximate analysis in longissimus dorsi was not different between animals fed the control diet and vitamin-supplemented diets. Vitamin C concentration in longissimus dorsi was higher (P<0.05) in the animals fed the vitamin C diet and the vitamin C plus E diet than in those fed the control diet and the vitamin E diet. Vitamin E concentration in longissimus dorsi was higher(P<0.05) in the animals fed the diet supplemented with vitamin E and the diet supplemented with vitamin C plus E than in those fed the control diet and the vitamin C diet. Animals fed the diet supplemented with vitamin C was higher(P<0.05) in myristic acid, palmitic acid, palmitoleic acid and oleic acid in the longissimus dorsi than those fed the other diets, but linoleic acid in longissimus dorsi was higher(P<0.05) in the animals fed the vitamin E diet than those fed the other diets. However, saturated fatty acid and unsaturated fatty acid were not different between animals fed the control diet and vitamin-supplemented diets.