ObjectiveTo investigate the therapeutic effect of Jiawei Jianpi Bushen prescription in liver fibrosis in rats and its effect on regulatory T (Treg) cells and T helper 17 (Th17) cells. MethodsA total of 32 male Wistar rats were randomly divided into normal group, model group, Jianpi Bushen prescription group, and Jiawei Jianpi Bushen prescription group. The model was established by subcutaneous injection of CCl4. The administration groups were given Jianpi Bushen decoction and Jiawei Jianpi Bushen decoction since week 4 and sacrificed at the end of week 8. The serum markers of liver function were measured, the status of liver inflammation and fibrosis was observed, and the protein and mRNA expression of Fox3 and interleukin-17 (IL-17) and serum levels of interleukin-4 (IL-4) and IL-17 were also observed. An analysis of variance was used for comparison of continueus data between multiple groups, the LSD t-test was used for comparison of countinuous data between two groups; the Ridit test was used for comparison of ranked data. ResultsCompared with the normal group, the model group showed significant increases in total bile acid (TBA), alkaline phosphatase (ALP), total bilirubin (TBil), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) (all P＜0.05), as well as significant collagen deposition in the liver and significantly increased expression of α-smooth muscle actin (α-SMA) (both P＜005). Compared with the model group, the Jianpi Bushen decoction group showed significant reductions in serum ALP, TBA, TBil, and ALT (all P＜0.05); the Jiawei Jianpi Bushen decoction group showed significant reductions in serum ALP, TBA, TBil, ALT, and AST (all P＜0.05); the administration groups showed significant reductions in collagen deposition in the liver and expression of α-SMA (all P＜0.05). Compared with the Jianpi Bushen decoction group, the Jiawei Jianpi Bushen decoction group had significantly reduced TBA, ALT, and AST (all P＜005). Compared with the normal group, the model group showed significant increases in the protein and mRNA expression of IL-17 in the liver tissue and a significant increase in the mRNA expression ratio of IL-17 to Foxp3 (all P＜0.05), a significant increase in serum IL-17 level, and significant reductions in serum levels of IL-4 and IL-17 (all P＜005). Compared with the model group, the administration groups showed significant reductions in the protein and mRNA expression of IL-17 in the liver tissue and a significant reduction in the mRNA expression ratio of IL-17 to Foxp3 (all P＜005), a significant reduction in serum IL-17 level, and significant increases in serum levels of IL-4 and IL-17 (all P＜005). ConclusionJiawei Jianpi Bushen prescription has improved efficacy in the treatment of liver fibrosis, and its mechanism of action may be associated with the regulation of Treg/Th17 imbalance.