Abstract: Objective To explore the anti-tumor effect and the mechanism of PHA-767491 against leukemia cells K562. Methods After different concentration of PHA-767491 acted on K562 cells, cell survival rate was detected by MTT at different time, the apoptosis signal pathway was examined by RT-PCR and Western blot, and cell apoptosis was checked by hochest staining and flow cytometry. Results PHA-767491 inhibited the proliferation of K562 cells significantly, by the way of reducing the expression levels of antiapoptotic protein Xiap and Mcl-1 significantly, and inducing cell apoptosis through Caspase pathway. Conclusion PHA-767491 could inhibit the proliferation of K562 cells significantly through inducing cell apoptosis, thus, it could be a new alternative leukemia drug in the future.