To observe the effects of electro-acupuncture at BL 40 on the expression of the type 1 IGF receptor (IGF1R) and IGF binding protein 3 (IGFBP3) in rats with multifidus muscle injury.Methods:A total of 90 male Sprague Dawley rats were randomly divided into blank group (BG)，model group (MG) and BL 40 electro acupuncture group (WG)，with 30 rats in each group.Then the rats in MG and WG were injected with 0.5% bupivacaine into both sides of L4-5 multifidus muscle.After model establishment，the rats in WG accepted electro-acupuncture once a day.The changes of IGF1R and IGFBP3 in 3 groups' multifidus muscle were observed and analyzed at 1st，2nd，3rd，7th and 14th day.Results:The expression of IGF1R at day 2，3，7，14 was higher than BG (P<0.05)，while WG was higher than MG at day 1 and day 2.The MG's expression of IGFBP3 was higher than BG's at day 7 and day 14.Compared with MG，the expression of IGFBP3 in WG decreased at day 2 and day 14.Conclusion:Electro-acupuncture at BL 40 could increase the expression of IGF1R and decrease the expression of IGFBP3，so as to promote the regeneration of tissue after multifidus muscle injury.