Objective To investigate the effects of transformin growth factor-beta (TGF-beta;) and interferon-gamma(IFN-gamma;)on collagen synthesis in human retinal pigment epithelial cells(RPE)． Methods TGF-beta;(0.01～10 ng/ml),recombinant IFN-gamma;(100～10000 Ｕ/ml)or a combination of two were added to cultures of RPE and collagen synthesis of the cells were measured by3 H-proline incorporation assay,indirect immunofluorescence staining and dot-blot hybridization. Results TGF-beta; at 10 ng/ml increased cell uptake of 3 H-proline to 130．87% of controls．It intensified Type IV,I and Ⅲ collagen fluorescent staining as well as mRNA expression．IFN-gamma; at 10000 Ｕ/ml caused 54．72% inhibition of 3 H-proline uptake by RPE,and decreased TypeⅣ collagen fluorescent staining as well as mRNA expression of Type Ⅳ,I and Ⅲ collagens. Conclusion TGF-beta; and IFN-gamma; stimulated and inhibited collagen synthesis of human RPE,respectively．The combination of two had antagonistic effects．IFN-gamma; can be used for inhibition of collagen synthesis of RPE. (Chin J Ocul Fundus Dis, 1999, 15: 245-248)