Objective To observe the expression and localization of cellular homolog FLICE-like inhibitory protein (c-FLIP) in the procedure of benign biliary stricture formation and discuss the significances. Methods The method of in situ hybridization was used in anastomotic tissues from 15 dogs (experimental group) in 2, 3, 4, 5, 6 months after bile duct injury and 15 matching sham operation dogs (sham operation group) for analyzing the expression and localization of c-FLIP and calculating the average integrated optical density of each slice. Stain cells were counted under the magnification field (×400) and at least 5 fields per slice were examined. The cells stained red in the nuclei and (or) the cytoplasm were positive cells. The signals meant: Negative for cells no stained, weak positive for the cells with nuclei and (or) cytoplasm stained pink; b positive for the cells stained the bright red; while middle positive for the cells stained between the both. The image analysis software (Image pro plus 4.5) was applied in the gland tissue and interstitial tissue in each slice to calculate the average integrated optical density for the expression of c-FLIP. Results In the experimental group, there were all b positive expressions of c-FLIP in the interstitial tissue at all the time points, mainly expressed in the cytoplasm of fibroblast and very little or almost no expression in the glandular tissue. Positive expression of c-FLIP in the interstitial tissue was significantly ber than that of gland tissue (Plt;0.05); There were no significant differences among each time point in either the interstitial tissue or gland tissue (Pgt;0.05). In the sham operation group, there were all weak positive expressions of c-FLIP in the interstitial tissue and gland tissue at all the time points and was no significant difference (Pgt;0.05), no difference between each phase (Pgt;0.05). The expression of c-FLIP in the experimental group was significantly higher than that in the sham operation group in the interstitial tissue at all the time (Plt;0.05), while no significant that in the gland tissue (Pgt;0.05). Conclusion After bile duct injury, the expression of c-FLIP in anastomotic interstitial tissue is sustainable, by which the continuing obstruction effect to apoptosis may have a close relationship with the formation of biliary benign stricture.