Objective To evaluate the efficacy of allogeneic stem cell transplantation (allo-HSCT) in treatment of hematologic malignancies and observe hematopoietic reconstitution, graft versus host disease (GVHD) occurrence,transplant-related complications and the outcome of disease.Methods 20 patients with hematologic malignancies cured by allo-HSCT were analyzed retrospectively. 15 males and 5 females patients were enrolled, and the median age was 39 (8-59) years. Mobilization of donor’ s stem cells using rhG-CSF program 3 days before transplantation.Conditioning regimen:the patients with HLA-matched used modified Bu/Cy programs,the patients with HLA-mismatched (with 1 to 3 loci mismatched) used the modified Bu/Cy+ ATG program; the patient with T-ALL and the patient with MM used Flu+Bu/Cy program. GVHD prevention programs: mycophenolate mofetil + cyclosporine + short course methotrexate. Results 20 patients were successfully engrafted,the median time of absolute neutrophil count (ANC) ＞ 0.5×109/L was 13 (12-17) days,the median time of Plt ＞ 20×109/L was 16 (12-23) days, and the hematopoietic reconstitution was rapid in those patients who were transplanted by the donors with the collected amount of CDh cells ＞ 2.5× 106/kg (recipient body weigh) or the collected amount of mononuclear cell ＞ 5.0×10s/kg (recipient body weigh).No severe hemolytic reaction occurred in 11 cases of blood group incompatibility between donor and recipient after transplantation,11 cases (55 ％) developed acute GVHD (aGVHD):4 cases Ⅰ degree aGVHD,4 cases Ⅱ degree aGVHD,2 cases Ⅲ degree aGVHD,1 case Ⅳ degree aGVHD,all patients were improved after treatment.All patients attained complete remission (CR) after transplantation.Follow-up 6 (2-14) months,1 patient died in 5 months after transplantation because of leukemia relapse, 1 case died in 4 months after transplantation because of self-disabling autoimmune hemolytic cyclosporine, chronic GVHD (cGVHD) and multiple organ failure,the remaining patients still were in CR state.Conclusion Allo-HSCT is the effective way to treat hematologic malignancies. Engraftment is closely related with the quantity of hematopoietic stem cells from donor.Blood group incompatibility was not an obstacle for transplantion.Relapse,GVHD,infection are the major cause of death after transplantation.