To observe the effects of different electroacupuncture intervention time on the expression of multifidus muscle fork protein(Foxo1)，Myostatin and myoblast differentiation factor(Myod)in rats with lumbar multifidus muscle injury. Methods:Male Sprague-Dawley rats were randomly divided into the blank group(BG)，model group(MG)，immediate/24 h/48 h electroacupuncture group(0 hG/24 hG/48 hG)，with 8 rats in each group. The lumbar multifidus muscle injury model was replicated with 0.5% bupivacaine in the multifidus muscle. Each electroacupuncture group started the electroacupuncture on both sides of the Weizhong(BL40)and Shenshu(BL23)at 0 h/24 h/48 h after modeling，and continuous intervention for 7 days. Western blot was used to detect the expression levels of Foxo1，Myostatin and Myod proteins in multifidus muscles of each group. Results:Compared with the BG，the expression of Foxo1 and Myod proteins in the MG significantly increased(P<0.01); Compared with the MG，the expression of Foxo1 and Myostatin in the 0 hG and 48 hG were decreased(P<0.01，P<0.05). The expression of Foxo1 and Myostatin in the 24 hG significantly decreased(P<0.01)，and Myod protein expression was significantly increased(P<0.01). Compared with the 24 hG，the expression of Myostatin protein in 0 hG increased(P<0.05)，and the expression of Myod protein in 0 hG significantly decreased(P<0.01); the expression of Foxo1 protein in 48 hG was significantly increased(P<0.01)，and the expression of Myod protein was significantly decreased(P<0.01). Conclusion:The best intervention time is 24 h after injury，wich can effectively promote multifidus muscle repairing.