The applications of allogeneic bone marrow transplantation (allo-BMT) are limited by the high risk of relapse with primary malignancy. The newly adaptive immunotherapy with donor lymphocyte infusions (DLI) can induce an effective graft-versus-leukemia (GVL) reaction leading to molecular remission and prolonged disease free survival in the majority of patients with relapse of CML and some other hematologic malignancies. Little is known about the mechanisms and the kinetics of GVL, however, increasing evidences show that in the case of existence of chimerism the mature donor T lymphocytes are activated by the specific leukocyte artigen presented in the surface of host antigen presenting cells (APC), resulting in exclusively elimination of leukocyte. Undesired side-effects are the development of graft-versus-host disease (GVHD) and the occurrence of pancytopenia in some patients. Infusions with selective T lymphocytes and G-CSF-mobilized peripheral blood stem cells (PBSC) are the promising treatment of DLI for more patients.