Abstract： Objective To investigate the effect of allgeneic hematopoietic stem cell transplantation (allo-HSCT) for β-thalassemia major. Methods Twenty-four β-thalassemia major patients with median age of 4 years (range: 2～15 years), 18 boys and 6 girls, received allo-HSCT.They were classified into class Ⅱ-Ⅲ according to Pesaro thalassemia classification. Twenty-three transplantations were from sibling donor and 1 was from mother, either HLA-identical (n = 23) or HLA-mismatched (5/6) (n = 1). Fifteen patients received bone marrow transplantation (BMT) plus peripheral blood stem cell transplantation (PBSCT), and 9 were subjected to umbilical cord blood transplantation (UCBT). The conditioning regimen consisted of busalphan, cyclophosphamide,fludarabine, plus hydroxyurea before transplantation. Graft-versus-host disease (GVHD) prophylaxis included CsA, methotrexate, antilymphpcute globulin, and mycophenolate mofetil. The median follow-up period was 13 months (range: 3～69). Results Of 24 patients, there were 21 cases (87. 5 %) of disease-free survival, 1 (4. 2 %) transplantation-related death, and 2 cases (8. 3 %) of rejection. Three-year overall survival and disease-free survival rate was 91.7 % and 87. 5 %respectively. The cumulative incidence of grade Ⅱ -Ⅳ acute GVHD and chronic GVHD was 16. 7 %and 20. 3 %, particularly cumulative extensive chronic GVHD was 5. 0 %. Conclusion The sibling donor BMT plus PBSCT is an effective and safe way to treat β-thalassemia major. Cord blood is an important source of hematopoietic stem cells for HSCT. The protocol GVHD prophylaxis of CsA,MTX, ATG with a low-dose and short course of MMF can effectively reduce the incidence of severe acute GVHD, improve the outcome of thalassemia transplantation.