In treating of leukemia and controlling of minimal-residual disease (MRD), graft versus leukemia effect (GVL) plays a critical role, and complicated mechanisms are involved in this immunology process. When graft cells are infused into recipients, the evoked GVL effect must be inevitably influenced by many factors derived from allogeneic effect between donor and receptor. To utilize GVL more efficiently in future clinical practice and to improve the curative effect of allo-HSCT, it is necessary to recognize these factors. Some potential factors influencing GVL such as chimerism patterns, autocytotoxic cells, dynamics of immune cells in patients, the cytokines and so on are reviewed in this article.