Half a month after leukemia stem cell transplantation, the white blood cells are around 4×10^9/L, while the neutrophil index does not rise, which may be caused by the body’s hematopoietic system has not yet been fully restored, but also can be seen in the primary or secondary implantation of poor and graft-versus-host disease. 1. Leukemia hematopoietic stem cell transplantation is a medical treatment mainly through high-dose radiotherapy and chemotherapy (fludarabine, leucovorin) to block the development of the primary disease, and then hematopoietic stem cell transplantation to rebuild the patient’s hematopoietic and immune system, so as to achieve the treatment of leukemia. Hematopoiesis cannot be restored immediately after bone marrow transplantation and requires a repair process. Neutrophils usually rise in about 4 weeks, and platelets may rise in more than 4 weeks, and with the prolongation of time, neutrophils and platelets may gradually return to normal. Therefore, it may be caused by the hematopoietic reconstruction that has not yet been completed. 2. This condition can also be seen in poor implantation after transplantation, which may be associated with donor-recipient blood group incompatibility, viral infection, or graft-versus-host disease. 3. In addition, this condition is commonly associated with graft-versus-host disease. Since the bone marrow is the target organ for the graft-versus-host effect, acute graft-versus-host disease after transplantation may be accompanied by slow hematopoietic reconstitution and other clinical manifestations. Specific diagnosis and treatment should be made under the supervision of a physician.