Abstract: 【Objective】 To study the effects of different doses of proanthocyanidins on serum antioxidant indexes before and after 1,000 m speed race in Yili horses. 【Method】 Sixteen Yili horse horses, aged 2 years and close to 1,000 m speed, were randomly divided into four groups. Four dose groups of proanthocyanidins were supplemented for 28 days, and 1,000 meters speed race was carried out on the 28th day. The sampling time was 30 minutes before the race, 30 minutes after the race, 90 minutes after the race and 24 hours after the race. Venous blood was collected to determine the related indexes, and the results were analyzed by single factor variance analysis. 【Result】 In resting state: the activity of SOD in the experimental group was significantly higher than that in the control group (P < 0.05). GSH-PX were significantly higher in the 60 mg/kg BW and 40 mg/kg BW than control group (P <0.05). 30 min after the game: SOD and GSH-PX were significantly higher in the 60 mg/kg BW and 40 mg/kg BW than the control group (P<0.05). MDA content was significantly lower in the 60 mg/kg BW than control group (P <0.05). 90 min after the game: SOD were significantly higher in the 60 mg/kg BW than the control group (P <0.05). GSH-PX were significantly higher in the 60 mg/kg BW than 40 mg/kg BW and the control group with 20 mg/kg BW (P <0.05). 24 hours after the game: SOD and GSH-PX were significantly higher in the 60 mg /kg BW than the control group (P <0.05). 【Conclusion】 The amount of procyanidins supplemented to exercise horses was controlled at 60 mg/kg BW can effectively promote the antioxidant capacity of the Yili horses.