Abstract: To investigate the influence of Pinus koraiensis bark polyphenols (PKBP) on antioxidant abilities in aged mice, a subacute aging mice model was built by neck back subcutaneous injection of D-galactose for 4consecutive weeks. Using VEas positive control, PKBP was given to mice by gavage at three different doses of50, 100mg/ (kg·d) and 200mg/ (kg·d) . The model control groups were given normal saline by gavage during that time. Total antioxidant capacity (T-AOC) , catalase (CAT) , total superoxide dismutase (T-SOD) , glutathione peroxidase (GSH-Px) , malondialdehyde (MDA) and protein carbonyl (PC) in the serum, liver and brain of mice were determined at the end of the last administration. The results showed that the content of T-AOC, T-SOD, CAT and GSH-Px in the aged model group significantly declined (p<0.05) , but the content of PC and MDA significantly increased, spleen and thymus index significantly decreased as compared to the normal control group (p<0.05) . For the aged mice treated with 100 and 200mg/ (kg·d) of PKBP, the activities of T-SOD, CAT, GSH-Px and the content of T-AOC significantly increased (p<0.05) , the content of MDA and PC significantly declined (p<0.05) , and spleen and thymus index increased as compared to aged control mice. These data indicated that PKBP could significantly improve the antioxidant capacity of subacute aging mice, and ease descent of immune function caused by aging with dose-effect relationship.