To explore the effects of Xiaochaihu Decoction on chronic hepatitis B and Th17/Treg cells.Methods:A total of 150 patients with chronic hepatitis B admitted to Beijing Chinese Medicine Hospital Shunyi Hospital were divided into a control group and an observation group，with 75 cases in each group.The control group was treated with Western medicine，and the study group was treated with Xiaochaihu Decoction.The changes of liver function，T lymphocyte subsets，liver death，CLDQ and Th17/Treg cells were observed and compared.Results:After the treatment，ALT，TBIL，GLB，ALB，PTA，TNF-α，CD3+，CD4+，CD4+/CD8+，CD8+，Treg，IL-10，TGF-β 1，Th17，IL-17，IL-23，ha，PC Ⅲ，Ⅳ-C，LN and clinical symptoms and signs of the patients in the observation group were significantly improved compared with those before treatment(P<0.05).Conclusion:Xiaochaihu Decoction can improve the liver function and immune function of chronic hepatitis B patients，improve liver fibrosis，improve survival treatment，and promote the balance of Th17/Treg cells.