The malondialdehyde （MDA）， oxymyoglobin （OMb）， metmyoglobin （MMb）， antioxidant enzymes activity （superoxide dismutase SOD； catalase CAT； glutathione peroxidase GSH-Px）， antioxidant ability （cupric reducing antioxidant capacity CUPRAC； radical scavenging ability RSA）， color and pH were determined to analyze the difference of antioxidant system in biceps femoris muscle （BF）， triceps brachii muscle （TB）， and longissimus dorsi muscles （LD） from Sunit sheep. The results showed that the SOD and CAT in TB were highest， while the CAT， CUPRAC， RSA in LD was highest. The pH in LD was highest， while the MDA， L*， a* and b* of LD were significantly lower than BF and TB （P<0.05）. The content of OMb in BF was significantly higher than TB and LD （P<0.05）， while the content of MMb was significantly lower than TB and LD （P<0.05）. The antioxidant enzymes in the muscles of Sunit sheep have synergistic effects， and the enhancement of antioxidant enzyme activity will improve the antioxidant ability and reduce the oxidation degree. Overall， the antioxidant substances content， the ability to remove free radicalsin and CAT in LD were highest； lipid oxidation degree was lower than BF and TB. Consequently， the LD has higher antioxidant ability than BF and TB.