AIM： To preliminarily discuss the mechanisms of cycloslporinc(CsA) on the IL-17⁺ cells in uveitis. METHODS: Fifteen HLA-B27 uveitis patients with active uveitis were involved in this study. Blood samples were taken from these patients for analysis of IL-17. The levels of IL-17 in the supernatants of PBMCs from patients before treatment cultured without or with CsA at different concentrations were detected by enzyme-linked immunosorbent assay (ELISA). Intracellular staining with flow cytometry was used to evaluate the expression of CD69 on the IL-17-producing cells in different groups. RESULTS: The results showed that CsA inhibited the secretion of IL-17,but it did not influence the expression of CD69. CONCLUSION: Our findings showed that one of the mechanisms of CsA on the treatment of HLA-B27 uveitis is the inhibition of the secretion of IL-17.