Abstract: AIM　To investigate the poteintation of vincristine-induecd apoptosis by tetrandrine, neferine and dauricine isolated from Chinese medicinal plants in the human mammary MCF-7 multidrug resistant cells. METHODS　The apoptotic cells were detected by fluorescent staining of a combination of Hoechst 33342 and propidium iodide (PI), flow cytometry and agarose electrophoresis. RESULTS　The apoptotic cells induced by vincristine alone accounted for about 10% of all the cancer cells, while the percentage of apoptotic cells induced by a combination of vincristine with tetrandrine, neferine, or dauricine was found to be significantly higher than that by vincristine alone, and their reversal effects were positively correlated with the drug concentration and the exposure time. In addition, tetrandrine was shown to be the most potent in the reversal efficacy among the three compounds to be tested for apoptosis in vitro. CONCLUSION　Tetrandrine, neferine and dauricine showed obvious potenitiation of vincristine-induced apoptosis in the human mammary MCF-7 multidrug-resistant cells.