1, leukemia in complete remission; 2, aplastic anemia with a full-phase donor; if hemiphasic conventional therapy is not effective and transfusion-dependent; 3, lymphoma stage III-IV; 4, relapsed refractory leukemia; 5, myelodysplastic syndrome. Transplantation is not required for low-risk or intermediate-risk acute lymphoid leukemia in children, but transplantation is more effective than chemotherapy in high-risk patients or relapsed refractory types.