Objective:To study the effect of obstructive jaundice on liver function and pathomorphology in rats.Methods:Sixty healthy male Sprague-Dawley rats were randomly divided into bile duct ligation (BDL) group (the common bile ducts were ligated,n=50) and sham group(the common bile ducts were isolated but not ligated,n=10).According to the ligation periods,BDL group was further divided into BDL3,BDL7,BDL14,BDL28 and BDL42 groups.Liver function indices, including the serum total bilirubin(TBIL),direct bilirubin(DBIL),total bile acid(TBA),and alanine aminotransferase(ALT), were measured; and the liver pathomorphology was observed 3,7,14,28,and 42 days after BDL.The above examinations were performed in the sham rats 7 days after operation.Results: The liver function of rats had obvious changes compared with that of sham group.The serum levels of TBIL,DBIL,and TBA reached the peak in the early phases (BDL3 or BDL7) and decreased gradually thereafter,but were still higher than that of the sham control in the end phase(BDL42).There was a similar change in the biochemical indices such as ALT.The main pathomorphology changes in BDL group were intrahepatic bile duct proliferation and hepatic fibrosis.Conclusion: There is obvious impairment in the early phase of obstructive jaundice; the liver function may be improved to a certain degree by a compensation mechanism; however,the persistence of obstructive jaundice finally leads to hepatic fibrosis.The liver function indicated by the pathomorphology changes can not reflect the actual impairment of liver tissue in obstructive jaundice rats.