【Objective】 To investigate the impact of ABO blood group compatibility and incompatibility(major /minor/bidirectional incompatibility) on the outcomes of patients underwent allogeneic hematopoietic stem cell transplantation(allo-HSCT), and to provide evidences for optimizing the transplantation program. 【Methods】 From January 2014 to June 2018, we retrospectively reviewed the clinical courses of 18 recipients of allo-HSCT from ABO-compatible donors and 52 from ABO-incompatible donors at our hospital. The implantation time of granulocyte/erythrocyte/megakaryoblast, RBC/platelet transfusions within 3 months posttransplantation, the initiating and completion time of ABO blood group conversion(for ABO-compatible donors only) were analyzed and compared among the ABO-incompatible and ABO-compatible donors as such variables including demographic data, donor and patient relationship, diagnosis of disease, bone marrow hematopoietic function prior to transplantation, HLA matching were not significant different. 【Results】 For 18 recipients of allo-HSCT from ABO-compatible donors, the implantation time of granulocyte, erythrocyte, megakaryoblast was 12.0(11.0~16.3), 41.5 (35.0~49.0) and 19.0(16.0~22.5)days, respectively. For 52 recipients of allo-HSCT from ABO-incompatible donors, the ABO blood group conversion was initiated at 28.0(22.5~44.0)days posttransplantation and completed at 105.5(85.0~141.8)days. In the ABO-compatible group, the time of erythrocyte implantation was shortened(P<0.05), and less RBC /platelet transfusions were required as compared with the ABO major and bidirectional incompatible group, except for the time of granulocyte and megakaryoblast implantation(P>0.05), no significant difference was observed between these two variables. The blood group conversion time, implantation time of granulocyte/erythrocyte/megakaryoblast, and RBC /platelet transfusions among ABO major, minor and bidirectional incompatible groups were not significant different (P>0.05). 【Conclusion】 ABO-compatiblity enjoys priority in allo-HSCT. ABO-incompatiblity can be chosen in the order of minor, major and bidirectional incompatibility in the absence of ABO-compatiblity.