Abstract: Objective To investigate the effect of eukaryotic expression vector mediated RNAi targeting Hoxa10 on the sensitivity of human Chronic Myeloid Leukemia K562 Cell line to daunorubicin. Methods shRNA oligo was designed and compounded according to the effective and specific siRNA strand from our previous test.Then plasmid pGPHI/GFP/Neo-Hoxa10 targeting Hoxa10 was constructed and sequenced.It was transfected into K562 cells by positive ion liposome.This experiment was divided into three groups:normal control group,negtive control group and experimental group(normal K562 cells,negative control plasmid transfect K562 cells and pGPHI/GFP/Neo-Hoxa10 transfect K562 cells).Different concentrations of DNR were added into these three groups,respectively.The drug sensitivity to DNR was detected by MTT assay.The apoptosis changes were detected by flowcytometry. Results The plasmid pGPHI/GFP/Neo-Hoxa10 was successfully constructed and transfected into K562 cells.The mRNA of Hoxa10 was inhibited by this plasmid in K562 cells by optical density rate=(38.864±4.488)%.The IC₅₀ in the experimental group to DNR was significantly reduced as compared with that in the control(P<0.05);and the sensitivity of K562 cells to DNR was elevated about 3.58 times.The apoptosis morphological rate of experimental group was(16.207±4.891)%,which was significantly different from that of the control groups(P<0.05);and the apoptosis morphological rate increased obviously after this vector combining DNR(P<0.05). Conclusion The expression of Hoxa10 can be effectively silenced by the eukaryotic expression vector pGPHI/GFP/Neo-Hoxa10,which can increase the sensitivity of K562 to DNR.