Abstract: Objective: To study the effects of sulindac on proliferation and apoptosis in gastric cancer cells and the probable mechanism involved.Methods: The BGC-823 cells were cultured with sulindac at various concentrations for different time.Morphological changes of BGC-823 cells were observed by inversion microscopy.The inhibitory rate of cell growth was assessed by MTT spectrophotometric analysis.The cell cycle distribution was measured by flow cytometry(FCM).The ultrastructure of cells and the apoptotic morphology were examined by transmission electronic microscopy.Apoptosis of the cells was examined by DNA electrophoresis.Results: Sulindac can make gastric cancer cells BGC-823 morphologic change,inhibit its growth and change the cells cycle distribution.The apoptotic morphology of BGC-823 cells were observed by transmission electronic microscopy.The notably DNA ladders of the cells apoptosis were detected by DNA electrophoresis.Conclusions: Sulindac can inhibit the BGC-823 cell proliferation and induce cell apoptosis,the mechanism may be related to changing cell cycle distribution and downregulate the expression of COX-2.