Abstract: OBJECTIVE To observe the effects of Shaoyao Gancao decoction on the imbalance of Treg/Th17 and their related cytokine in rats with asthma, and to explore its mechanism in treating asthma. METHODS SD rats, ♂, were randomly divided into normal control group, model group, Shaoyao Gancao decoction group, dexamethasone group and integrated TCM-WM group(n=8 for each group). Asthma was induced by intraperitoneal injection of ovalbumin (OVA) and forced inhalation of atomized OVA. Expression of IL-2, IL-6, IL-10 and IL-17 was detected by Elisa method. Numbers of CD4⁺ T cells in spleen was analyzed by flow cytometry. RESULTS Compared with model group, expression of IL-6, IL-17 and IL-2 in lung homogenate were decreased significantly in the treated group(P<0.01) and expressions of IL-10 was significantly increased in the treated groups(P<0.01). There were no significant differences of expression of IL-2, IL-6 and IL-10 among the treated groups(P>0.05). Expression of IL-17 was decreased significantly in the dexamethasone group than other treated groups(P<0.05). Compared with model group, Shaoyao Gancao decoction increased the percentages of CD4⁺CD25⁺Foxp3⁺ regulatory T cell(P<0.01). CONCLUSION Shaoyao Gancao decoction can efficiently regulate the imbalance of Treg/Th17 and their related cytokine, which may be one of its mechanisms in preventing and treating asthma.