Abstract: Objective To evaluate the clinical efficacy of L-ornithine-L-aspartate combined with Lactulose in treatment of hepatic encephalopathy.Methods 80 patients with hepatic encephalopathy due to severe hepatitis or liver cirrhosis were randomly divided into treatment group (n=42) and control group (n=38) .The treatment group was treated with L-ornithine-L-aspartate by intravenous drip and Lactulose by clyster, the control group was treated with Arginine by intravenous drip and 0.9% sodium chloride solution by clean sausage.Course of the two groups were 7 days, before and after treatment, clinical data including main symptoms and signs, serum ammonia, hepatorenal function of the two groups were monitored respectively and their clinical effect change were evaluated.Results Total effective rate of the treatment group (81.0%) was higher than that of the control group (52.6%) (P<0.01) .After treatment, the AST, ALT, TBil and serum ammonia of the treatment group were significantly lower than those before treatment (P<0.05, P<0.01) , serum ammonia of the control group was also declined after treatment (P<0.05) .There were significant different for AST, TBil and serum ammonia between the two groups (P<0.05) .The degree of hepatic encephalopathy of the two groups improved after treatment (P<0.05, P<0.01) , the treatment group were better than the control group in improving the degree of hepatic encephalopathy (P<0.05) .Conclusion L-ornithine-L-aspartate combined with Lactulose has good clinical efficacy in improving hepatic function and hepatic encephalopathy.