Abstract： Objective To compare RNA interference (RNAi) with imatinib in killing K562 cells. Methods Design effective shRNA sequences special for bcr-abl silencing and insert them into the eukaryotic expression vector for RNAi by gene engineering. The recombinant plasmi(ts were then transfected into K562 cells. 48 hours later, the efficiency of transfection was identified by fluorescent microscope, bcr-abl mRNA level was detected by RT-PCR. Another group of K562 cells were treated respectively by imatinib with different concentration. All groups of K562 cells were finally analyzed in apoptosis, cell proliferation and phosphotyrosine-containing proteins. Results Both RNAi and imatinib induced apoptosis, decreased proliferation and reduced phosphotyrosine-containing proteins. Conclusion BNAi can kill K562 cells successfully as imatinib, and it may be a promising way to treat CML patients in clinic, especially for those who fail in imatinib or other chemotherapy.