The study was aimed to evaluate the yield of the COBE Spectra blood cell separator with auto-peripheral blood stem cell program for collection of peripheral blood hematopoietic stem cells (PBHSC) from HLA-matched ABO-incompatible allogeneic PBHSC donor, and observe the safety and effect of allogeneic peripheral blood hematopoietic stem cell transplantation (allo-PBHSCT) without removal of erythrocytes and plasma. PBHSC from 28 allogeneic donors were collected by COBE Spectra blood cell separator with auto-peripheral blood hematopoiEtic stem cell (auto-PBHSCT) program. Control group included 15 HLA-matched patients who received allo-PBHSCT with ABO-compatible grafts. The amount of PBHSC was harvested and the parameter was modified according to the hematocrit and mononuclear cell (MNC) counts of donors. The nucleated cell count, proportion of MNC, number of CD34(+) cells were detected, and reconstitution status of hematopoietic function and time for change into donor's blood group were observed. The results showed that the nucleated cell count proportion of MNC and number of CD34(+) cells showed no significant difference between groups of ABO incompatible and compatible (p > 0.05). All their hematopoietic functions were reconstituted. Between the ABO incompatibility and the compatible groups, the time of neutrophil and platelet recovery was not significantly different (p > 0.05), In ABO blood major incompatible and the compatible groups, the recovery of erythropoiesis were significantly delayed (p < 0.01). The blood type of 18 patients in ABO incompatible group was turned into donor's blood type successfully at 35-139 days after transplantation. It is concluded that major ABO incompatibility did not affect the erythropoiesis reconstitution in HLA matched allo-HSCT. the major incompatibility may be a main reason of erythropoietic delay.