Abstract: The aim of this study was to investigate the in vitro and in vivo antioxidant effects of Kunlun chrysanthemum oleoresin. Kunlun chrysanthemum oleoresin was obtained by using supercritical fluid CO₂ taken Kunlun chrysanthemum as raw material. The fatty acids of Kunlun chrysanthemum oleoresin were analyzed by GC-MS. The scavenging rate on ·OH,DPPH· and total reducing ability of Kunlun chrysanthemum oleoresin were measured in vitro. The activity of superoxide dismutase(SOD),the content of malondialdehyde(MDA)and the ability of total antioxidant(T-AOC)in serum,liver and kidney of mice were measured in vivo.The results showed that 12 kinds of fatty acids were detected in the Kunlun chrysanthemum oleoresin,including 4 kinds of unsaturated fatty acids,accounting for 53.28% of the total fatty acids,among which the relative content of linoleic acid was 22.81%,linolenic acid was 10.84%,and oleic acid was 7.29%. In vitro experiments showed that Kunlun chrysanthemum oleoresin had scavenging effects on ·OH and DPPH· in varying degrees,and the scavenging effect increased with the increase of oleoresin concentration,and its total reducing ability was weak. The IC₅₀ values of Kunlun chrysanthemum oleoresin on ·OH and DPPH· were(0.7768±0.0675)and(0.8160±0.2219) mg/mL,respectively. In vivo experiments showed that in the middle and high dose group of Kunlun chrysanthemum oleoresin,the activity of SOD in serum,liver and kidney was significantly increased(P<0.05),the content of MDA in serum and liver was significantly decreased(P<0.05),and the ability of T-AOC in liver and kidney was significantly enhanced(P<0.05). However,the effect of Kunlun chrysanthemum oleoresin on the total antioxidant capacity of serum and the content of MDA in kidney was not significant. Therefore,the appropriate dosage of Kunlun chrysanthemum oleoresin can enhance the antioxidant function of the body.