Abstract: Forty adult patients undergoing non-cardiac major surgery were divided into 2 groups. Group A (n=20) was anesthetized by balanced intravenous procaine anesthesia and guoup B(n=20) by epidural block. Blood Volume, Cortisol, aldosterone, Glucose, Insulin, TT_3 TT_4, rT_3, ATG and MCA levels in plasma were measured from 24 hours before operation to 48 hours after operation. The mechanism of these changes and clinical significances was discussed.