Objective To investigate the effect of celastrol on reducing osteoclast formation in rat bone marrow culture and occurrence of local inflammation and bone erosion in Collagen-induced arthritis（CIA ）mice by inhibiting the expression of chemokine CXCL2. Methods CIA models of mice were randomly divided into three groups：control group， arthritis group and celastrol group， observing the inflammation by pathological staining technique， detecting the changes of CXCL2 expression in local joints and blood serum by real-time fluorescence quantitative PCR and ELISA. Osteoclast was induced by bone marrow in rat in which celastrol of different concentration was added in vivo test， detecting the changes of CXCL2 expression by real-time fluorescence quantitative PCR. Results High CXCL2 expression in pre-osteoclast and CIA mice was observed. And celastrol can inhabit its expression in dose-dependent manner. Conclusion Cel may inhibit the expression of chemotactic factor CXCL2 and inflammatory cells from invading the organization， thus reducing the tissue destruction.