This study was aimed to establish sensitized animal models, explore the changes of immune function in these sensitized recipients, and investigate effects of sensitization on the engraftment of hematopoietic stem cells (HSCs). Different doses of spleen cells (1x10(5), 1x10(6) and 1x10(6)x2 at intervals of 7 days) from C57BL/6 were infused into BALB/c, the immunity function of sensitized models was tested by complement-dependent cytotoxicity method, mixed lymphocyte reaction and ELISA. After irradiation with gamma-ray of 60Co in dose 8 Gy, sensitized mice were transplanted 1x10(7) C57BL/6 bone marrow cells via tail vein or intra-bone marrow, and survival rate was detected daily. The results showed that different levels of donor reactive antibody were induced in all sensitized models. Comparing with normal mice, profound proliferation of spleen cells were found in groups of injected 1x10(6) and 1x10(6), continuous injections at intervals of 7 days. Sensitized model received bone marrow cells of C57BL/6 via tail vein died on day 10 to 14 after transplantation, and sensitized model mice received bone marrow cells of 1x10(6)x2 at intervals of 7 days via intra-bone marrow also died within two weeks after transplantation. It is concluded that different sensitized mouse models are established by different doses of allogeneic spleen cells infusion, the changes of immune function in sensitized mice are correlative with sensitization. Donor HSCs are rejected in sensitized models, and the engraftment can not be improved by intra-bone marrow injection.