Purpose : This study was aimed to investigate the inhibitory effect of Leonurus sibiricus on the proliferation of human uterine leiomyoma cells and the expression of gene related the mechanism of cell apoptosis. Methods : We counted the number of death cells treated with indicated concentration of Leonurus sibiricus and investigated cell death rate by MTS assay. Furthermore, flow cytometry analysis and DNA fragmentation assay were used to dissect between necrosis and apoptosis and then we observed the differential gene expression by western blot analysis. Results : Leonurus sibiricus significantly inhibited the proliferation of uterine leiomyoma cell in a dose-dependent and time dependent manner. Fluorescence activated cell sorter (FACS) analysis indicated that Leonurus sibiricus induced G1 cell cycle arrest. Leonurus sibiricus enhanced the expression of p27 and p53 with cell cycle arrest. Conclusion : These findings suggest that Leonurus sibiricus is a candidate agent for the treatment of uterine leiomyoma. p27, $p53^{1}$ may play an important role in Leonurus sibiricus-induced cell cycle arrest and cell growth inhibition. sibiricus;