AIM: To explore the effect of Gui Zhi decoction on enteric mucosal immune in type Ⅱ collagen-induced arthritis (CIA)in DBA mice.METHODS: Eighty DBA/1, weighing 18-22 g, were randomly divided into four groups with 20 in each group:control group, CIA group, treatment groups at high dosage and low dosage (GZH and GZL). CIA was induced by immunization with type Ⅱ collagen (CⅡ) emulsified with equal complete adjuvant at 0.1 mg CⅡ each mouse. Blood lymphocyte suspension was screened for CD4 and CD8 expression using a flow cytometry, the CD4 and CD8 and secretory IgA (sIgA)-positive cells in enteric lamina propria tested with immunohistochemical staining. Tumor necrosis factor-alpha (TNF-α), interleukin-L (IL-1)-β, and IL-6 concentrations in serum were assayed with RIA.RESULTS: Gui Zhi decoction can lower the arthritic scores and decrease the occurrence of arthritis. The CD4, CD8,and sIgA-positive cells in CIA mice are less than in control mice, and in Gui Zhi decoction at high dosage could restore the lowered CD4- and CD8-positive cells in lamina propria,and at both high and low dosages could increase the lowered sIgA-positive cells in lamina propria, even still lower than in normal mice. In periphery, the CD4 cells in periphery are higher in CIA mice than in control mice,and Gui Zhi decoction at high and low dosages could decrease the CD4 and CD8 cells. Also, Gui Zhi decoction at high dosage could decrease the IL-6 and TNF-αconcentration in serum.CONCLUSION: Gui Zhi decoction can lower the arthritic scores and decrease the incidence of CIA in mice, and the mechanism is in part regulating enteric mucosal immune.