Abstract: In order to clarify the effect of H₂O₂ treatment on energy metabolism,apoptosis and tenderization in the postmortem aging of Tibetan sheep meat.The Longissimus dorsi （LD） of Tibetan sheep was selected as the experimental material,Tibetan sheep meat was treated with distilled water,50 mmol/L and 200 mmol/L reactive oxygen activator hydrogen peroxide,and then aged at 4℃for 0 d,0.5 d,1 d,3 d,5 d and 7 d.The changes in ROS relative content,ATP content,Ca²⁺-ATPase and Na⁺/K⁺-ATPase activity,apoptosis rate,myofibril fragmentation index （MFI） and muscle fiber diameter during postmortem aging were tested.The results showed that after aging of 7 d,the relative content of ROS in the 50 mmol/L H₂O₂ treatment group was 39.19%significantly higher than that of the control group （P＜0.05）,the ATP content,Ca²⁺-ATPase and Na⁺/K⁺-ATPase activity and muscle fiber diameter of 50 mmol/L and 200 mmol/L H₂O₂ treatments were 25.73%and 25.77%,38.39%and36.70%,27.30%and 29.46%,and 13.68%and 13.94%significantly lower than that of the control group （P＜0.05）,the apoptosis rate and MFI in the two treatment groups were 63.07%and 50.42%,and 5.74%and 5.19%significantly higher than that of the control group （P＜0.05）.To sum up,the H₂O₂ treatmented Tibetan sheep meat could promote ROS production,change energy metabolism of the Tibetan sheep meat,improve the activity of apoptosis,and promote the meat tenderization.It provided a theoretical basis for improving the quality of Tibetan sheep meat.