Objective：To explore the impact of rapamycin on compensatory bile duct growth in response to ischemic injury.Methods: Male SD rats were randomly assigned to 4 groups:sham (n=28),sham+rapamycin ( rapa，n=28 ),ischemia (n=32),ischemia+rapa group (n=32).Complete hepatic arterial deprivation was performed in the latter 2 groups; gastric lavage with rapamycin (2 mg/kg/day ) was given to rats in rapa groups.Fresh liver tissues were obtained on day 1,3,7,and 14 postoperatively and were subjected to immunohistochemical staining (H-E,Ki-67).Interlobular bile duct within portal tract and periportal bile ductuli were counted in H-E stained sections.Ki-67 positive and negative bile duct epithelial cells were counted in Ki-67 immunolabelled sections.Average interlobular ducts,periportal duculi and ratio of Ki-67 positive epithelial cells／negative epithelial cells were calculated.Results: Ischemia group had obviously increased number of interlobular ducts compared to sham group.Rapamycin lavage inhibited interlobular duct increase on day 7 and day 14 postoperatively compared with ischemia group.In ischemia group Ki-67(+)/(-) ratio reached its peak level (1.59±017) 3 days after operation,being significantly higher than that of sham group.Rapamycin decreased the peak value of Ki-67(+)/(-) ratio.Conclusion: Rapamycin can reduce expression of Ki-67 antigen and inhibit compensatory bile duct proliferation in response to ischemic injury.