Abstract: Objective: To investigate the effects of transforming growth factorβ₁(TGF-β₁) on the proliferation of human retinal pigment epithelium(RPE) cells by ³H-thymidine deoxyribose(³H-TdR) absorption,and explore the pathogenesis mechanism of vitreoretinopathy.Methods: Human retinal pigment epithelium cells were cultured in vitro,the cells were incubated with 0.1,1.0,5.0,10.0 and 100.0μg/L of TGF-β₁.The radioactivity intensity of cells were determined by ³H-TdR absorption.Results: The 0.1,1.0,5.0 and 10.0μg/L of TGF-β₁ could promote the proliferation of RPE cells to increase the number of living cells,the intaking ³H-TdR value of cells was significantly higher than that in control group(P<0.01).The effects of the 100.0μg/L of TGF-β₁ on the proliferation of RPE cells was opposite,the intaking ³H-TdR value of cells was significantly lower than that in control group(P<0.01).Conclusions: The effect of TGF-β₁ on the proliferation of RPE cells is dual regulation,different concentrations of TGF-β₁ may have different effects on RPE cells.The effect of TGF-β₁ on promoting the proliferation of RPE cells maybe one of mechanisms of proliferative vitreoretinopathy.