Abstract: Objective:To observe the influence of hemodilution autotransfusion (HAT) combined with controlled hypotension (CH) on the coagulation and liver function of orthopedic surgery patients.Method:Thirty patients with orthopedic surgery who selected HAT were randomly divided into 2 groups. One group using simply acute normovolemic hemodilution (ANH) autotransfusion, 400 ml blood obtained from an elbow vein of left upper extremity was stored in the sodium citrate blood collection bag, while 6% hydroxyethyl starch injection and equilibrium liquid were transfused rapidly through an elbow vein of the right upper extremity, and routine anesthesia was performed. The other group using ANH combined with CH, both in the ANH mean arterial pressure (MAP) of 70% of the target parallel with nicardipine CH. Venous blood specimens were collected at ANH before immediately (T₀), ANH completed immediately (T₁) and ANH completed 1h (T₂), respectively to detect thromboplastin time (APTT), prothrombin time (PT), coagulation time (TT) and total bilirubin (TBIL), alanine aminotransferase (ALT), aspartate aminotransferase (AST).Result:At time T₁ and time T₂, Hb/Hct of 2 patients were lower than those at T₀(P＜0.05). The differences of coagulation and liver function between the two groups showed no statistical significance (P＞0.05).Conclusion:When they had no significant cardiovascular disease, the application of ANH combined nicardipine parallelled CH would had no significant influence on different periods coagulation and liver function of orthopedic patients who fit autotransfusion conditions, which would be safe, feasible and worth in clinical practice.