Objective This study investigates the protective effect of bicyclol on liver function in patients after liver resection.Methods One hundred and twenty patients undergoing liver resection with Pringle's maneuver were randomly divided into groups A,B,and C,and given bicyclol (50 mg),diammonium glycyrrhizinate (150 mg),and silybum marianum (77 mg),respectively.The medication was orally given preoperatively for 5 days and postoperatively for days 3 to 7.The fasting serum ALT,AST,TB,ALP,and PAB levels were determined before operation and on days 1,3,5,and 7 after operation.Results ALT levels in the A group were significantly lower than those in the B and C group on post operative days 1,3,5,and 7 (P＜0.01).On postoperative day 7,the ratio of serum ALT returned to normal was significantly higher than the B and C group ratios (P＜0.05).Conclusion Therefore,oral bicyclol given before and after liver resection can significantly inhibit the rapid increase and promote the normalization of serum ALT levels.