Cholangiocarcinoma is a malignant tumor originating from extrahepatic bile ducts including the bile ducts from the hilar region to the lower end of the common bile duct. The age of onset of bile duct cancer is mostly 50-70 years old, and the trend of youthfulness is obvious in recent years. The incidence of bile duct cancer in China is less common than other malignant tumors in the digestive tract such as gastrointestinal and liver tumors, but the prognosis is poor. Therefore, we should not ignore about bile duct cancer. The bile duct can be divided into the gallbladder, which temporarily stores bile, and the bile duct, which connects to the duodenum. Bile is a digestive fluid that assists fat digestion. When food enters the stomach, it will output bile from the gallbladder to the duodenum, and there is a papillary part at the exit near the duodenum, which is normally closed in order to prevent excessive bile output. Cancer of the gallbladder, which is the passage of bile, is called gallbladder cancer, and cancer of the bile duct is called bile duct cancer, and the two together are called biliary tract cancer. According to the data in 2001, about 15,000 people died of biliary tract cancer every year, and there is a tendency to increase in recent years. In particular, the incidence of gallbladder cancer is more common in women than in men. The 5-year survival rate for gallbladder cancer is 20% to 40%, and the number of cases that can be operated on surgically is 20% to 30%. In addition, the 5-year survival rate for bile duct cancer is 30% to 40%, with the most cancers developing in the upper part of the bile duct. The most influential factor in the development of biliary tract cancer is gallstones. This is because gallstones denature the bile accumulated in the gallbladder and bile ducts and affect the mucosa. About 5% to 7% of people with cancer in the gallbladder area develop biliary tract cancer, and 50% to 70% of gallbladder cancer patients have gallstones.