The proliferation-promoting effects of corn oligopeptides(COP) on HL-7702 cells in vitro were studied by MTT assay and flow cytometry(FCM).Results indicated that COP could stimulate the growth of hepatocyte,and the promotion increased in a concentration-dependent manner over the range of 1~10 g/L;the proportions of cells in S and G2/M phases of cell cycle were increased at 24h after the addition of COP;and in this concentration range,the influence of COP on cell viability and morphology were not significant.COP could enhance human hepatocyte line HL-7702 proliferation and DNA synthesis,and also can improve the vitality of hepatocyte.The study suggested that COP could have certain effect on liver protection.