Abstract: Abstract: In order to study the effect of flaxseed supplementation on the flavor quality of Sunit lamb , a total of 24 healthy sheep (four months old) were randomly allotted to two experimental groups fed on diets containing flaxseed at 0 (control group) and 8% (flaxseed group), respectively. The sheep were slaughtered after being fed for three months, and the longissimus dorsi muscle was taken for subsequent tests. In this experiment, the volatile flavor substances were determined by gas chromatography mass spectrometry. The electronic nose was applied to determine odor profile of the meat. In addition, the antioxidant capacity of the meat was measured to explore the relationship between antioxidant capacity and volatile flavor substances. The results showed that the growth performance and carcass mass in control group were similar to that of flaxseed group, and the difference was not significant(P>0.05). Flaxseed supplementation increased the richness of volatile flavor substance and affected its composition and content. The critical volatile flavor substances of Sunit lambs include 1-octen-3-ol, heptanal, (E)-2-octenal, octanal, (E)-2-nonenal, nonanal, (E)-2-decenal and decanal. The content of hexanal(13.78%)and nonanal(11.12%) in control group were significantly higher than flaxseed group(P<0.05). Flaxseed significantly increased the content of pentanal(4.37%), (E)-2-octenal(1.41%) and decana(1.35%)(P<0.05). Principal component analysis can distinguish the flavor of the two groups of lamb, indicating that the flaxseed supplementation had an effect on the critical flavor substance of the meat between two groups. Electronic nose result showed that flaxseed supplementation affected the overall flavor profile of the Sunit lambs and decreased the odor intensity. The radical scavenging ability (RSA) in flaxseed group was 58.09% and total antioxidant capacity (T-AOC) reached 0.53 U/mg，which significantly higher than control group (P<0.05). Correlation analysis showed that antioxidant system has a correlation with volatile flavor substances. Catalase (CAT) was significantly positively correlated with (E)-2-decenal (P<0.01). RSA was significantly positively correlated with (E)-2-octenal, (P