Ｏｂｊｅｃｔｉｖｅ　To evaluate the influence of moderate hypothermia anesthesia on brain injury in the operation of repairing Stanford type A aortic operation.　Methods　A total of 82 patients underwent Stanford type A aortic operation were divided into two groups: deep hypothermia (anus temperature 25 ℃, nasopharyngeal temperature 20 ℃) (DH group) 40 cases and moderate hypothermia anesthesia group (anus temperature 28 ℃, nasopharyngeal temperature 25 ℃) (MH group) 42 cases respectively. Two groups of patients were anesthetized in the same manner. MH group was cooled to nasopharyngeal temperature 25 ℃, circulation was stopped when anal temperature reached 28 ℃. DH group was cooled to nasal cavity temperature 20 ℃, circulation was stopped when anal temperature reached 25 ℃. Surgery were conducted by the same set of performer. S-100β and neuron specific enolase(NSE) blood concentration were measured from blood taken from bottom of jugular vein ball at time points prior to the cut lesion (T0), before stop the circulation (T1), after circulation restored (T2), postoperative 4 h (T3), 24 h after surgery (T4) and 72 h after surgery (T5). In addition, the time of general anesthesia, the time of cooling, the time of reheating, the time of the operation, the changes of the pupil during the perfusion, the blood loss after the shutdown, the blood flow of the blood cells and the amount of blood plasma were recorded. Postoperative period of waking time, conjunctival edema, surgical restlessness, neurological complications, postoperative management time, duration of ICU, duration of hospital stay were also recorded and analyzed.　Results　Compared with DH group, MH group in general anesthesia time, cooling time, thawing time, operation time, awake time, chemosis, restlessness, neurological complications, postoperative with tube time, ICU stay time, total days in hospital were decreased (P<0.05). Blood bleeding volume after the machine shutting down, blood transfusion and blood plasma volume were decreased (P<0.05). The blood concentration of S-100β and NSE was significantly reduced at T1, T2 and T3 (P<0.05).　Conclusions　Moderate hypothermia anesthesia in Stanford type A aortic operation can help reduce brain injury and can be used as a preferred scheme.