Objective To evaluate the effect of ulinastatin on hepatic ischemia-reperfusion injury in patients with hepatic alveolar echinococcosis in plateau region.Methods Sixty patients with hepatic alveolar echinococcosis in plateau region,weighing 45-75 kg,aged 30-55 yr,of American Society of Anesthesiologists physical status Ⅰ or Ⅱ,scheduled for elective partial hepatectomy,were divided into control group (C group) and ulinastatin group (U group) using a random number table,with 30 patients in each group.Ulinastatin 12 000 U/kg (in 100 ml of normal saline) was infused intravenously at 20 min before occlusion of hepatic portal in group U,and normal saline 100 ml was given instead in group C.Before operation,at 10 min after occlusion of hepatic portal,at 20 min and 1 h after unclamping hepatic portal and at 12 h after operation,blood samples were collected from the right internal jugular vein for determination of the levels of serum alanine aminotransferase,aspartate aminotransferase and malondialdehyde.Results Compared with group C,the levels of serum alanine aminotransferase,aspartate aminotransferase and malondialdehyde were significantly decreased at 20 min and 1 h after unclamping hepatic portal and 12 h after operation in group U (P＜0.05).Conclusion Ulinastatin can attenuate hepatic ischemia-reperfusion injury in patients with hepatic alveolar echinococcosis in plateau region.