Objective To study the treatment effect of compound ovalbumin proteolysis liquid(COPL) on the hypoproteinemia in dogs and rats. Methods Ligation of common bile duct was performed to induce the cholestasis in 25 female and 25 male beagle dogs. One hundred and fifty male Sprague-Dawley (SD) rats were first given phenobarbital sodium (i.g.) for 1 week, then they were treated with carbon tetrachloride (CCl4, 40%-50%, 1.25 ml/kg, i.p., twice a week) combined with edible alcohol (10%) for 8 weeks. Another 150 male SD rats received exairesis operation of right kidney, and then were treated with adriamycin twice (5 and 3 mg/kg, i.p. on the first and forth week after operation, respectively). The serum levels of serum albumin (SAB), total serum protein (TSP), alanine transaminase(ALT), total bilirubin (TB), creatinine (Cr), and urinary nitrogen (UN) were observed. Animals with SAB level lower than 30 g/L were taken as successful model. The model animals were randomly divided into 5 groups: model control group, 3 COPL treatment groups (low, middle and high dose groups) and non-fat milk group. After treatment for 2 weeks, the animals were killed and the sera were collected for detection of these parameters again. Results The levels of SAB were significantly increased (P<0.05,P<0.01) in meddle and high dose COPL groups and the levels of ALT were significantly decreased (P<0.05,P<0.01) in all the 3 COPL groups in all the 3 hypoproteinemia models. Other indices had no significant changes (P>0.05). Conclusion COPL has satisfactory effect on the hypoproteinemia both in the dogs and rats. Moreover, it has protective effect on the hepatic function.