Blood transfusion is known as a route of therapeutic in anemic animals, but little desire has been shown due to lack of the basic information. The aims of this study were to investigate the undesirable reactions of blood transfusion, amount of injection and the level of condolence in anemic cows. Twenty two anemic cows with PCV 16.8 were selected. In each animals the mean 5.36 blood units with average 42 days stored in 4°C was transfused. Blood samples for biochemical, hematological and enzymes activity were collected before infusion, after injection, 2, 4, 6, 24, 48 and 72 hours. Respiratory rates (RR), heart rates (HR), ruminal movements (RM) and body temperature m were also recorded. The results of Hest showed that the mean PCV, Hb, RBC, WBC, K, AST, RR, HR in anemic cows increased (P<0.05). It is concluded that RBC, Hb and PCV are the main blood parameters in blood transfusion which directly effects RR, HR, T and facilitate curity in cows. Biochemical components and enzymes activity are less important. Secondly, infusion of one blood unite increases approximately one -mite in PCV, Thus the level of PCV is more important in amount of blood transfusion. All animals cured after treatment.