Objective To study the effect of the ECV-304 cells modified with LIF gene on the ex vivo culture of HSC/HPC in cord blood.Methods The ECV-304 cells were infected by Eukaryotic Expression plasmid pcDNA3.0LIF,and the positive ECV-304 cells were obtained by selected with G418.These cells were used to co-culture with CD34+ cells of cord blood.The phenotype of CD34+ and CD34+ CD54+、CD34+ CD62L+ primitive progenitors was detected by flow cytometry.Results The LIF gene can express in ECV-304 cells steadily.ECV-304 cells modified with LIF gene can improve expansion of CB CD34+、CD34+CD54+ and CD34+ CD62L+ cells while sustaining the expression of homing-related adhesion molecule.Conclusion The ECV-304 cells modified with LIF gene can not only significantly expand CB hematopoietic progenitor cells ex vivo,but the expanded CD34+ cells may well retain their homing ability.