 Leukemia cells can be killed by natural killer NK from HLA-I mismatched donor. The proposed study plans to realize an adoptive anti-leukaemic immunotherapy by infusion of HLA-I mismatched NK cells to treat poor prognosis acute myeloid leukemia patients. NK cells will be selected from HLA mismatch familial donor peripheral mononuclear cells by purification protocol. Before NK-infusion, patients received immunosuppressive chemotherapy. 