Microtransplantation is an important research result of our Department of Hematology in PLA 307 Hospital in the past 10 years. More than 200 cases have been successfully performed. The cure rate is significantly higher than that of chemotherapy alone. No graft-versus-host disease (GVHD, i.e., rejection) occurred. A significant graft-versus-leukemia effect (GVL) can be observed. Patients in the low-risk and standard-risk groups achieved a cure rate of 75%, approaching full-phase transplantation. Microtransplantation is a new transplantation concept developed on the basis of clear and non-clear marrow transplantation. It is based on highly effective chemotherapy combined with in vitro treated donor mobilized post-hematopoietic stem cell transfusion; without GVHD prophylaxis and immunosuppressive therapy, forming donor microchimerism in patients, inducing GVL/GVT effect while avoiding GVHD, stopping treatment after 2-4 courses of sequential therapy, and follow-up observation. It is a transplantation method between autologous and allogeneic transplantation. Microtransplantation is suitable for people with: acute leukemia, multiple myeloma, myelodysplastic syndrome, malignant lymphoma, etc., with no matched HLA match but a mismatched donor willing to donate HSCT. Patients request to do it in remission, if multiple chemotherapy is not in remission or has relapsed it is not suitable for microtransplantation. High risk patients and relapsed refractory patients are first recommended for classical allogeneic HSCT.