AIM:To investigate the action of Rg3 in the inhibition of human lens epithelial cells SRA01/04 in vitro and its possible mechanism.METHODS:SRA01/04 cells were cultured in medium containing 10% fetal bovine serum.10,20,40,80,120,160μg/mL Rg3 was added in medium respectively in experimental group,and the control group was set without Rg3.Effects of Rg3 on SRA01/04 proliferation were evaluated by MTT colorimetric assay.The morphology change of SRA01/04 cells was observed by the acridine orange(AO)/ethidium bromide(EB)staining.The flow cytometry was used to detect the apoptotic rates of SRA01/04 cells at 48 hours after Rg3 treated.RESULTS:The inhibiting rate of Rg3 on SRA01/04 cells was gradually enhanced in 10,20,40,80,120,160μg/mL Rg3 added group,showed a dose-dependent and time-dependent manner.We could observe the phenomena of budding and the formation of apoptosis body by fluorescent microscope.The apoptotic rates of SRA01/04 cells showed an increasing tendency in Rg3 added group with increase of Rg3 concentration(F=15.326,P=0.000).CONCLUSION:Rg3 can remarkably inhibit the proliferation and induce the apoptosis of SRA01/04 in vitro