Object To evaluate the significance of double common bile duct （DCBD） in hepatobiliary surgery. Metheds The data of diagnosis and treatment of two patients with DCBD in our hospital between Jul. to Dec. 2010 were analyzed retrospective， and the related literatures were reviewed. Results The right hepatic bile duct of DCBD due to mistaking it for cystic duct in 1 case was accidental injuried during laparoscopic cholecystectomy. Another example，the DCBD was confirmed by intraoperative exploration and choledochoscopic examination， at the same time with chole-dochal cyst， anomalous pancreaticobiliary ductal junction （APBDJ）， primary hepatolithus， and choledocholith， and then operation was performed. Two cases were typeⅤb of DCBD. A total of 32 English literatures were reviewed. Since the beginning of 1932 English literature had reported 100 cases of DCBD. The type Ⅱand typeⅢwere the most common type of DCBD， and the typeⅤonly 10 cases. There were 27 cases of DCBD in twenty-five Chinese articles from 1994 to 2012. The typeⅤwas the most common type of DCBD. The accessory common bile duct （ACBD） opening in the duod-enum， gastric， and pancreatic duct were the most common. The common complications included stone， APBDJ， choled-ochal cyst， tumor etc. Conclusions DCBD is a very rare anatomic variation of extrahepatic bile duct， often accompanied by calculus of bile duct and common bile duct cyst， APBDJ， and other biliary anatomy abnormality， and potentially carci-nogenic potential. The existence of DCBD may increase the risk of iatrogenic bile duct injury and complexity of biliary operation. In view of this， this abnormality of extrahepatic duct should be paid with close attention during operation.