Aim To evaluate the effect of ZST93 on the proliferation in human chronic myeloid leukemia(CML)cells(K562)and explore the possible mechanism.Methods MTT assay, cell growth curve and inverted microscope were used to investigate the effect of ZST93 on proliferation of K562 cells.Cell transfection and Western blot were performed to detect the autophagy, while PI staining, Annexin V-FITC/PI and flow cytometry were conducted to determine cell apoptosis and its anticancer mechanism.Results ZST93 could significantly inhibit the proliferation of K562(IC50=2.59 μmol·L-1)and induce cell cycle arrest at G1-phase in a dose- and time-dependent manner.Also, through leading to accumulation of GFP-LC3, transition into LC3- II from LC3- 1 , and decrease of p62 expression, ZST93 induced autophagy initiation and autophagic flux.Furthermore, ZST93 induced extrinsic apoptotic pathway by activating caspase-8, and further promoted the cleavage of apoptosis related proteins including caspase-9, caspase-3 and PAR P.Moreover, Z-DEYD-FMK, the specific inhibitor of caspase-3 , could dramatically reduce the apoptosis induced by ZST93.Taken together, ZST93 could effec tively inhibit CML cells, arrest eell cycle at G,-phase, induce cell apoptosis anrl initiate autophagy.Conclusions The potential mechanism may he related to the regulation of autophagy intiation/caspase-8/caspase-3 signaling pathway, which provides a new idea and theoretical basis for the treatment of CML.