The relapse leukemia patients after transplantation were divided into two groups randomly. Group D1: patients received first-donor stem cells infusion(DSI) treatment with or without chemotherapy; group D2: patients received second-donor DSI treatment with or without chemotherapy. The second donors were preferably donors who were genetically related and had more HLA-match locus. The re-induction chemotherapy regimen was primarily MAT(mitoxantrone, cytarabine, Teniposide ) for acute myeloid leukemia (AML) and VMCLD(vincristine, Teniposide, cyclophosphamide, L-Asparaginase, Dexamethasone) for acute lymphocytic leukemia (ALL), and no graft versus host disease(GVHD) prevention was conducted pre- and post- therapy.