Abstract: Objective TO evaluate the security and effects of acute non-isovolemic hemodilution (ANIH) combined with autogolous blood transfusion on aged patients undergoing total hip replacement. Methods Sixty aged patients undergoing total hip replacement were randomly divided into 2 groups(n=30 each): ANIH combined with autogolous blood transfusion group(group A) and autogolous blood transfusion group (group B). MAP, CVP, HR and ECG were monitored continuously during the operation. Hb, Hct, PT and APTT were detected before anesthesia induction (T0),5 minutes after hemodilution(T1),immediately after the completion of the expansion of the femoral medullary cavity and the cleaning of the acetabulum (T2),before reinfusing the autogolous blood(T3),at the end of the operation(T4). Record the volume of blood loss and autogolous blood,the volume and rate of allogenic blood transfusion ,the adverse reaction of blood transfusion .Results After hemodilution, Hb and Hct significantly decreased（p＜0.01）, the CVP of group A significantly increased compared with 5 minutes after anesthesia induction（p＜0.01）.At T2, CVP of group A was significantly higher than that of group B (P ＜0.05), Hb and Hct of group A significantly decreased compared with group B（p＜0.05）. At T4 , Hb and Hct of group A were significantly higher than that of group B (P ＜0.05).In group A, APTT prolonged markedly after hemodilution（p＜0.05）.There was no significant difference in blood loss,the volume and rate of allogenic blood transfusion of group A were significantly lower than that of group B (P ＜0.05). Conclusion ANIH has little influence on hemodynamics and blood coagulation of aged patients, and ANIH combined with autogolous blood transfusion is more effective .