Objective:To study the mechanisms that acupuncture therapy of "Shuanggu Yitong" in treating postmenopausal osteoporosis(PMO).Methods:60female SD rats aged 6 months were resected bilateral ovaries and feeded for 90 days in order to make the model of experimental osteoporosis.Then,they were divided into 5 groups such as control group,regular acupoints treated group,"Shuanggu" group,"Yitong" group,"Shuanggu Yitong" group,with 12 rats each group,and the control group without any treatment;Pishu(BL 20),Weishu(BL 21),Shenshu(BL 23),Qihaishu(BL 24) was selected for the regular acupoints treated group;Guanyuan(RN 4),Zusanli(ST 36) for the "Shuanggu" group;and Shenshu(BL 23),Geshu(BL 17),Dazhu(BL 11) for the "Yitong" group;Guanyuan(RN 4),Zusanli(ST 36),Shenshu(BL 23),Geshu(BL 17),Dazhu(BL 11)for the "Shuanggu Yitong" group.Electroacupuncture therapy was given once a day,15 minutes each time,the needles were retained for 10 minutes.Then these rats rested for 1 day after consecutive therapy for 6 days.The therapy lasted for 12 weeks.RT-PCR was used to examine the expression level of interleukin-6(IL-6)mRNA in bone tissue.Results:Compared with control group,the expression level of IL-6mRNA in all acupuncture therapy groups decreased(P0.05).Conclusion:Acupuncture can reduce the expression level of IL-6mRNA in osteoporosis model rats without ovaries and "Shuanggu Yitong" acupuncture therapy is superior to other regular acupuncture therapy.