Objective · To observe the effect of intra-bone marrow injection (IBMI) of fetal liver mononuclear cell suspension on reconstructing the hematopoietic system in mice. Methods · The fetal liver mononuclear cells the mice with gestational age of 13.5 days were obtainedFicoll separation technique, and then the hematopoietic stem cells (HSCs) were obtainedmagnetic bead sorting. The fetal liver mononuclear cells were injected into the tibias of 137Cs irradiated miceIBMI. The recipient mice were observed for reconstitution of the hematopoietic systemroutine blood examination, blood smear and bone marrow smear. The donor HSCs in the bone marrow of the recipient mice was subjected to flow cytometry 1 year after transplantation. Results · HSCs accounted for 0.171% in the mofetal liver mononuclear cells. One week after transplantation of mofetal liver mononuclear cells, blood cells derived donor cells were detected peripheral blood; in the third week after transplantation, peripheral blood leukocytes, red blood cells and hemoglobin of recipient mice were restored to the pre-irradiation levels; the percentage of donor-derived blood cells in peripheral blood in the fifth week was stable; the HSCs in the bone marrow of recipient mice were derived donor cells 1 year after transplantation. Conclusion · The murine fetal liver mononuclear cells can efficiently reconstruct the hematopoietic system of miceIBMI.