Objective: To observe the effects of immunosuppressants triptolide (TL) and cyclosporine A (CSA) on HLA antigens expression induced by interferon-γ(INF -γ) in vitro.Method: By using an indirect immunofluorescent method and analysing with ACAS-570, the abnormal HLA antigen expression of cultured ceal epithelial cells was induced by INF-γ. After incubation with one of the immunosuppressants (CSA, TL) for 72 hrs, the amount of HLA-A BC and HLA-DR antigens was measured.Result: There was no significant difference ( P ＞ 0.05) between the group with CSA and the positive control group without CSA. In contrast to CSA, TL dramatically inhibited INF-γ induced expression of HLA antigens of ceal epithelial cells (P＜0.001), compared with the control group without TL.Conclusion: TL had direct inhibition on the expression of HLA-ABCand HLA-DR antigens induced by INF-γin vitro, while CSA had no obvious inhibition. Eye Science 2000; 16:34 ～ 37.