AIM:To characterize the expression of members of the transforming growth factor-beta(TGF-β)/Smad/connective tissue growth factor(CTGF)signaling pathway in the tissue of benign biliary stricture,and to investigate the effect of TGF-β signaling pathway in the pathogenesis of benign biliary stricture.METHODS:Paraffin embedded materials from 23 cases of benign biliary stricture were analyzed for members of the TGF-β/Smad/CTGF signaling pathway.TGF-β1,TβRⅠ,T13RⅡ,Smad4,Smad7 and CTGF protein were detected by immunohistochemical strepto-advidinbiotin complex method,and CTGF mRNA was evaluated by hybridization in situ,while 6 cases of normal bile duct served as controls.The percentages of positive cells were counted.The correlation between TGF-β1,Smad4 and CTGF was analyzed.RESULTS:The positive expression ratios of TGF-β1,TβRⅠ,T13RⅡ,Smad4,CTGF and CTGF mRNA in 23 cases with benign biliary stricture were 91.3%,82.6%,87.0%,78.3%,82.6% and 65.2%,respectively,significantly higher than that in 6 cases of normal bile duct respectively(vs 33.3%,16.7%,50.0%,33.3%,50.0%,16.7%,respectively,P＜0.05).The positive expression ratio of Smad7 in cases with benign biliary stricture was 70.0%,higher than that in normal bile duct,but this difierence is not statistically significant 70.0% vs 50%,P＞0.05).There was a positive correlation between positive expression of TGF-β1,Smad4 and CTGF in cases with benign biliary stricture.CONCLUSION:The high expression of TGF-β/Smad/CTGF signaling pathway plays an important role in the pathogenesis of benign biliary stricture.