Abstract：Objective：To observe the efficacy and possible mechanism of electroacupuncture in the treatment of rheumatoid arthritis（RA）. Methods： A total of 48 male SD rats were randomly divided into the normal group， the model group， the electroacupuncture group and the Methotrexate group， with 12 rats in each group. Except for the normal group，the remaining groups were subcutaneously injected with 0.1 mL complete Freund's adjuvant through the tail root to induce the adjuvant arthritis rat model. The normal group and the model group were gavaged with 2 mL 0.9% sodium chloride solution daily for 21 days；the electroacupuncture group was given daily electroacupuncture once at the selected acupoints of the Shenshu（BL 23），Zusanli（ST 36），Sanyinjiao（SP 6）and Kunlun（BL60）lasting for 30 min for 21 days. The Methotrexate group was given 2 mg/kg Methotrexate solution by gavage once a week， three times in total. After intervention，the bone destruction degree of rats in each group was detected by animal Micro-CT，the foot volume of rats in each group was detected by limb volume measuring instrument，the ratio of Th1 helper cell and Th2 helper cell was detected by flow cytometry，and the levels of INF-γ and interleukin-4（IL-4）in serum were detected by ELISA. Results：After the intervention，compared with the normal group，the bone destruction in the model group was more obvious，the foot volume was increased（P＜0.05），the scores of foot swelling and Th1/Th2 and INF-γ level were up-regulated（P＜0.05），the body mass and the IL-4 level were reduced（P＜0.05）. The bone destruction of rats in the electroacupuncture group and the Methotrexate group was significantly improved when compared with those in the model group，the IL-4 levels were increased（P＜0.05），the foot volume was decreased（P＜0.05），the scores of foot swelling，Th1/Th2，and INF-γ levels were downregulated（P＜0.05）. Compared with the Methotrexate group，Th1/Th2 and IL-4 level in the electroacupuncture group were increased（P＜0.05）. Conclusion： The electroacupuncture can improve the bone destruction of RA rats，whose mechanism might be to restore immune homeostasis by regulating the Th1/Th2 ratio，increasing the body mass and the IL-4 level.