Cholangiocarcinoma refers to a malignant tumor of the extrahepatic bile duct that originates from the confluence of the left and right hepatic ducts to the lower end of the common bile duct. Cholangiocarcinoma can be divided into three types: hilar cholangiocarcinoma or upper cholangiocarcinoma, middle cholangiocarcinoma, and lower cholangiocarcinoma. Primary cholangiocarcinoma is rare, accounting for 0.01% to 0.46% of ordinary autopsies, 2% of autopsies of tumor patients, and 0.3% to 1.8% of biliary surgeries. In Europe and the United States, gallbladder cancer is 1.5 to 5 times that of bile duct cancer, while Japanese data show that bile duct cancer is more common than gallbladder cancer. The male to female ratio is about 1.5 to 3.0. The age of onset is mostly 50 to 70 years old, but it can also be seen in young people.