Abstract: OBJECTIVE To explore the effect of Rhein lysinate on cell cycle of HeLa cells and its mechanism. METHODS The effect of Rhein lysinate on cell proliferation was detected by MTT. The level of reactive oxygen species and the change of cell cycle of HeLa cells were investigated by flow cytometry. Cell morphology was observed by microscope. The expression of p53 and p21 was determined by Western blot. RESULTS Rhein lysinate could inhibit the proliferation of HeLa cells in a dose-dependent manner. The IC50 was approximately 83 μmol·L^-1. The level of reactive oxygen species and the ratios of S period and G2 period cells were increased following the increase of Rhein lysinate. Moreover vacuolar degeneration was induced with the increasing of Rhein lysinate. The phosphorylation of p53 and the expression of p21 were also increased. However the expression of p53 was not increased in accordance with the increase of Rhein lysinate. CONCLUSION Rhein lysinate inhibits the proliferation of HeLa cells by increasing the levels of reactive oxygen species, improving the phosphorylation of p53 and the expression of p21, presenting vacuolar degeneration and inducing the S period and G2 period block.