Objective To investigate inhibitory effects of matrine (Ma) combined with vincristine (VCR), cytosine arabinoside (Ara-c), harringtonine (HRT), adriamycin (ADM), and daunorubicin (DNR) on proliferation of K562 cells. Methods MTT colorimetric assay was used to detect the inhibition rate of Ma combined with antineoplastic on K562 cells. Results The proliferation of K562 cells was inhibited by Ma at the concentration of 160 ?g/ml to 400 ?g/ml. The inhibitory rates of Ma combined respectively with VCR, Ara-c, HRT, ADM, and DNR were significantly higher than those of VCR, Ara-c, or HRT alone (P0.05). Conclusion Ma can inhibit the proliferation of K562 cells in a dose-dependent manner. The anti-proliferation effect of VCR, Ara-c, and HRT on K562 cells could be enhanced by Ma.