Objective To observe the effect of Safflower polysaccharide(SPS) on the cell proliferation and apoptosis of human gastric carcinoma cell line SGC-7901.Methods SGC-7901 cells were processed with different concentrations of SPS during the same period.The morphology changes and proliferation of SGC-7901 cells were observed wiht inverted microscope.The apoptosis of SGC-7901 cell was detected by acridine orange(AO) assay.Results SGC-7901 cells in SPS group showed bad refraction,shrink,and more dead cells in culture medium were observed.Results of AO fluorescent staining showed part of SGC-7901 cells of cytoplasm condensed,chromatin increased,and the crescent-shaped shrinkage could be seen in some cells nucleus.Conclusion SPS can markedly inhibit the growth of SGC-7901 cells and induce apoptosis of gastric carcinoma cell line SGC-7901 in vitro cultured in a time-and dose-dependent manner.