To observe the therapeutic effect of electroacupuncture(EA) on obese mice, and to explore the underlying mechanism of EA in treating obesity by focusing on the balance of regulatory T cells (Treg) and T helper 17 cells (Th17) and related inflammatory factors. C57BL/6J male mice were randomly divided into normal group, model group and EA group, with 10 mice in each group. The obesity model was established by feeding the mice with high-fat diet. Mice in the EA group was treated with EA at "Zhongwan"(CV12), "Guanyuan"(CV4), "Zusanli"(ST36) and "Fenglong"(ST40) for 20 min every time, 3 times every week, for a total of 8 weeks. The food intake and body weight of mice were observed and recorded, and Lee's index was calculated; the contents of interleukin 2(IL-2), IL-4, IL-6, IL-10, IL-17A, gamma interferon (IFN-γ) and tumor necrosis factor(TNF)-α in serum were detected by multiplex liquid chip quantitative technique; the levels of Treg and Th17 cells in mice spleen tissues were detected by flow cytometry; and the expression levels of foxhead box p3(Foxp3) and retinoic acid related orphan receptor γt(ROR-γt) mRNA in spleen were detected by real-time quantitative PCR. Compared with the normal group, the food intake, body weight, Lee's index, the contents of IL-2, IL-6, IL-17A, IFN-γ and TNF-α in the serum, and the percentage of Th17 and expression of ROR-γt mRNA in the spleen tissues were significantly increased (P<0.01, P<0.001), while the contents of IL-4 and IL-10 in the serum, the percentage of Treg and expression of Foxp3 mRNA in the spleen tissues were significantly decreased (P<0.001, P<0.01) in the model group. Compared with the model group, the food intake, body weight, Lee's index, the contents of IL-2, IL-6, IL-17A, IFN-γ, and TNF-α in the serum, the percentage of Th17 and expression of ROR-γt mRNA in the spleen tissues were significantly decreased (P<0.01), while the contents of IL-4 and IL-10 in serum, the percentage of Treg and expression of Foxp3 mRNA in the spleen tissues were significantly increased(P<0.01, P<0.05) in the EA group. EA may improve the obese state of mice by regulating the balance of Treg/Th17 in spleen and the expression of inflammatory factors in serum.