Abstract: Objective To explore the difference of bile duct and hepatocyte damage caused by different doses of Clonorchis sinensis infection in rabbits, and to provide reference for the establishment of models.Methods The metacercarias of clonorchis sinensis were extracted by artificial digestion, collected and counted under microscope. 400, 600 and 800 metacercarias were given to 15 rabbits by oral in 3 groups named low-degree, medium-degree and high-degree infected group, normal saline was given to 5 rabbits which were served as control group. All rabbits were sacrificed after 90 days and the liver specimens were performed with pathological examination.Result sRabbits in 3 infected groups were all infected successfully. Egg positive rates in feces reached 100% in 4 weeks post infection. The highest adult Clonorchis sinensis recovery rate in low, medium and high infected-groups were 20.50%,15.17% and 23.38%. There was no statistical difference in the number of adults between the low and medium infection groups（P=0.24）,the comparison of number of adults between low and medium infected-groups with high infected-group showed significant differences（P<0.01）. The rabbit liver in the infected group was found that biliary ducts in the liver were thickened significantly, and a large number of live adult Clonorchis sinensis were found in the intrahepatic bile ducts and gallbladder; Observed with light microscope, the portal area was enlarged with collagen accumulation, the intrahepatic bile duct was thickened, the bile duct wall was thickened, the bile duct and surrounding tissues were inflamed, and low to high level intraepithelial neoplasia was observed in the endothelium of the bile duct. Masoon trichromic staining was observed and stage of fibrosis was quantified according to the Metavir scoring system -- liver fibrosis staging score. In the control group, 5 rabbits were all in the stage of F0 (no liver fibrosis), while in the infected group 2 were in the stage F1, 4 were in the stage F2, and 4 were in the stage F3, There was statistical difference in the stage of fibrosis between low and high infection groups（P<0.05）.Conclusions Infection for 90 days, the best recommended dose for Clonorchis sinensis infection model in rabbit is 600 metacercarias, it was suitable to the requirements for experimental model as biliary duct injury and hepatic fibrosis.

Key words: Clonorchis sinensis, Animal model, Rabbit, Biliary duct injury, Hepatic fibrosis