To compare the inhibition ratio of different concentration triamcinolone acetonide （TA）on retinal pigment epithelium (RPE) cells, retinal glial (RG) cells and epiretinal membrane(ERM) cells, and find the lowest effective concentration for ERMs cells up to maximum inhibition rate to guide clinical PVR prevention METHODS: Effect of TA with different concentraion(08, 0.6, 0.4, 0.3, 0.2, and 0.1mg/mL) on RPE cells, RG cells, and ERMs cells cultured in vitro was detected by methyl thiazolyl tetrazolium (MTT) assay. RESULTS: Three kinds of cells needed TA with different concentraion when they got the maximum inhibition ratio. The lowest effective concentration for RPE cell was 0.4mg/mL, that for ERMs cell was 0.8mg/mL and for RG cell was 0.6mg/mL. Inhibition ratio and time of drug action were positively related. CONCLUSION: TA can inhibit all kinds of cellular proliferation; but the concentration is different for three kinds of cells. The ERMs cells need higher concentration than RPE and RG cells.