〔Abstract〕 Objective To explore the effect of GANT 61 on collagen induced arthritis(CIA) mice. Methods BALB/C mice were randomly divided into three groups [Control group, collagen induced arthritis(CIA) group, GANT61 group].CIA group and GANT61 group were induced arthritis with bovine type Ⅱ collagen. GANT61 group was injected with GANT61 on 0, 3, 6, 9, 12, 15, 18, 21 d after second immunization. Meanwhile the condition of joints was observed and the clinical score was made. On 39 th day after primary immunization, mice were executed to collect peripheral blood and serum for detecting the change of neutrophils and cytokines. Joints and synovial tissues were collected for pathological examination and synovioblast culture. Cell proliferation was detected by flow cytometry and CCK-8 assay. Apoptosis was detected by flow cytometry. Results Data showed that GANT61 could reduce joint swellingand clinical score of arthritis,the infiltration of inflammatory cells can also be reduced.Neutrophils and inflammation cytokines of interferon-gamma(IFN-γ), interleukin-6(IL-6), tumor necrosis factor-α(TNF-α). GANT61 could remarkably inhibit cell proliferation and induce cell apoptosis. Conclusion GANT61 can alleviate the pathological progress of arthritis in Balb/c mice by inhibiting the proliferation of synovial fibroblasts.