Objective To explore the effect of proteasome inhibitor bortezomib (BOR) on proliferation inhibition and apoptosis in imatinib-resistant chronic myeloid leukemia cell line K562/G01. Methods MTT assay was used to observe the effect of growth inhibitory of cells; flow cytometry was used to detect cell cycle and apoptosis. Results K562/G01 cells was not sensitive to imatinib,1C50 values of imatinib to K562 and K562/G01 cells was (20.09±1.38) and (0.54±0.13) μmol/L,respectively; BOR could inhibit proliferation in K562/G01 cell,peaked at 48 h,and IC50 value of BOR to K562/G01 was (23.10±2.71) nmol/L. G2/M phase cell cycle arrest and significant apoptosis peak could be seen by flow cytometry with increased in the concentration and action time of BOR. Conclusion BOR can inhibit proliferation and induce apoptosis in imatinib-resistant K562/G01 cell,the mechanism may be related to cell cycle G2/M phase arrest.