Abstract: OBJECTIVE To study the effects of α-terpineol on adjuvant arthritis(AA) rats induced by Freund's complete adjuvant. METHODS After establishment of animal model of adjuvant arthritis, the rats were treated with 0.18, 0.35, 0.7 mg·kg^-1 α-terpineol, and the tripterygium glycosides group, model group, and control group were set as well. The degree of joints swelling, the level of IFN-γ, IL-4 in these groups were observed. RESULTS Compared with the model group, in the 0.35, 0.7 mg·kg^-1 α-terpineol group and the tripterygium glycosides group, the degree of joints swelling was obviously decreased(P<0.01), and the level of IFN-γ, IL-4(P<0.05) was adjusted. CONCLUSION α-Terpineol can effectively improve the symptoms of AA rats and reduce the degree of joint swelling, may be due to its upregulation of the level of IL-4, and down regulation of the level of IFN-γ.