Abstract: Objective To study the clinical curative effect and complications of allogeneic peripheral blood hematopoietic stem cell transplantation(HSCT) in the treatment of acute leukemia. Methods From February 2008 to February 2014,allogeneic peripheral blood hematopoietic stem cell transplantation was used in our department to treat 45 cases of patients with acute leukemia,including 24 cases of acute myeloid leukemia,19 cases of acute lymphoblastic leukemia,1 case of accelerated phase chronic myelogenous leukemia and 1 case of blastic phase chronic myelogenous leukemia.Bu and Cy were used as conditioning regimen for HSCT,Ara-c+Bu/Cy was used for HLA-haploidentical/mismatch donors,and additional Me-CCNU for patients with suspected central nerve involved.The graft versus host disease(GVHD) was prevented by using Ciclosporin A+short-course methotrexate(MTX)+mycophenolate mofetil(MMF),and additional antithymocyte globulin(ATG) for HLA-haploidentical patients.After the treatment,patients were followed up to February 2014 and the outcome was evaluated. Results All the 45 patients were implanted completely,with hematopoietic reconstruction,and the median survival time was 19 months(2-63 months).There were 10 cases of death,4 cases died for recurrence,4 cases died for GVHD,secondary tumor(non-hodgkin’s lymphoma) in 1 case,2 intracranial hemorrhage in 1 case death,and the rest were followed up to now,and 3 year disease-free survival in 6 cases. Conclusion As the development of HLA match technology,transplantation related complications prevention and supporting treatment,allogeneic hematopoietic stem cell transplantation will become a safe and effective treatment method for hematologic malignancies.