Abstract： Objective To analysis the effectivity and safety of haploidentical stem cell transplantion combined with unrelated cord blood infusion in the treatment of leukemia.Methods 44 patients were treated by haploidentical stem cell transplantion combined with unrelated cord blood infusion from January 2011 to May 2012,including 16 cases of acute lymphoblastic leukemia (ALL),24 cases of acute myeloid leukemia (AML),3 cases of chronic myeloid leukemia (CML) and 1 case of T lymphoblastic lymphoma.Results The median number of CD34+ cells was 3.14×106/kg (1.68×106/kg-8.32×106/kg) in the haploidentical grafts and 1.03×105/kg (0.31×105/kg-5.32×105/kg) in the cord blood units.42 (95.45 ％) patients acquired hematopoietic reconstruction.The median time was 14 d (10-29 d) for neutrophil engraftment and 23 d (11-89 d) for platelet engraftment.42 patients were on long-term monitoring for STR,except 5 (11.90 ％) patients relapsed in 3-13 months after transplantation,STR of other 37 (88.10 ％) patients were all higher than 95 ％.17 (40.47 ％) patients experienced acute graft-versus-host disease (aGVHD),the degree was Ⅱ-Ⅳ in 8 patients (19.05 ％),and Ⅲ-Ⅳ in 4 patients (9.52 ％).23 (54.76 ％) patients had chronic graft-versus-host disease (cGVHD),including 17 (40.47 ％) cases of localized type and 6 (14.29 ％) cases of diffuse type.The one year overall survival (OS) rate was 70.84 ％ and event-free survival (EFS) rate was 63.34 ％.Conclusion Haploidentical stem cell transplantion combined with an unrelated cord blood infusion is safe and effective in the treatment of leukemia,which may provide a new approach to allogeneic hematopoietic stem cell transplantation.