Objective To explore the role of chemokine CCL5 in the patients with juvenile idiopathic arthritis(JIA).Methods CCL5 in peripheral mononuclear and synovial fluid was examined by using real-time PCR and intracellular flow cytomer.Results There was highly increased CCL5 level in the synovial fluid,while low level in peripheral blood.No CCL5 was detected in the normal controls.CCL5 was mainly expressed in T cells and activiated T cells expressed increased CCL5 compared with un-activiated T cells.Conclusion Abnormal highly expressed CCL5 may contribute to the local inflammation of JIA.