Objective To explore the effects of bile from anomalous parcreaticobiliary ductal union (APBDU) patients on the growth of hunan cells of bile ducts, and the relationship between APBDU with bile duct carcinoma. Methods Bile sample from APBDU patients and normal persons were used for cells of bile ducts. The proliferative effect of bile was measured by mathabenzthiazuron (MTT) assay; Cell cycle and apoptosis were analyzed by flow cytometry (FCM); Expression level of c-erbB-2 was detected by Western blot assay. Results Bile from APBDU patients significantly promoted the proliferation of human cells of bile ducts compared with normal bile (P<0.05). The effect was abolished by addition of COX-2 inhibitor or iNOS inhibitor. The percentage of S period cells in group pretreated with APBDU bile was significantly increased compared with pretreated with normal bile (P<0.001). The expression level of c-erbB-2 was increased in cell pretreated with APBDU bile. Conclusion Bile from APBDU patients can promote the proliferation of normal cells of bile ducts and may have potential carcinogenesis.