Abstract: Objective To investigate the effect of donor lymphocyte infusion (DLI) for preventing relapse of leukemia after haplotype hematopoietic stem cell transplantation (HSCT), and evaluate the therapeutic effect and the safety of DLI. Methods The 20 haplotype HSCT patients who received DLI were studied for the occurrence of graft-versus-host disease (GVHD) and long-term survival. Results Eleven of twenty patients survived leukemia-free for a median of 25(4-60) months, and leukemia-free survival rate was 55 %. 9 cases died of relapse. 19 patients occurred acute GEHD (aGVHD) after received DLI, 4 of them were severe.Conclusion The prophylactic DLI is effective for preventing from relapse of leukemia. It might be feasible option.