Clinical blood transfusion is one of the most important supportive therapy for patients with tumor. The blood transfusion has dual effects for patients with tumor. First, blood transfusion can rectify anemia and improve oxygen saturation, accelerate oxidation and necrosis for tumor cells; the second, blood transfusion can induce immunosuppression, tumor recurrence and postoperative infection for tumor patients. Filtering white blood cells (WBC) before blood transfusion can decrease the incidence of the adverse reactions. The rational perioperative autotransfusion for patients with tumors is focus to which the world medical sciences pay close attention. In this article, the support effect of blood transfusion for treatment of tumor patients, blood transfusion and immunosuppression, blood transfusion and postoperative infection and relapse of tumor patients, depleted leukocyte blood transfusion and autologous transfusion of tumor patients are reviewed.