The present invention provides an antioxidant composition and/or a composition for improving skin conditions, which contain, as active ingredients, probiotics and vitamin C. The composition containing probiotics and vitamin C as active ingredients according to the present invention can exhibit a synergistic effect on the activation of antioxidant enzyme, thereby exhibiting an antioxidant effect and a skin condition improving effect. In addition, the composition containing probiotics and vitamin C as active ingredients according to the present invention can more effectively induce antioxidant effects to activate energy metabolism in vivo, thereby exhibiting a significant synergistic effect on weight loss.