Congenital cystic dilatation of the bile ducts is a congenital cystic dilatation of the intrahepatic or (and) extrahepatic bile ducts. vater (1723) first reported a case of common bile duct cysts (cholendochalcysts). caroli (1958) described in detail cystic changes of the intrahepatic bile ducts. This condition is also considered to be a benign tumor of the bile duct. Its etiology is not well understood and is associated with abnormal pancreatic and bile duct cohesion and chronic pancreatic reflux. Complications include: cholangitis, biliary cirrhosis, portal hypertension, gallstones, ruptured cysts, malignancy, etc. There are significantly more females than males with these patients, and about 75% of cases are diagnosed before the age of 10 years. In some patients, clinical symptoms do not manifest until the adult stage. In adults, congenital choledochal cysts are characterized by abdominal pain, jaundice, fever, and abdominal masses as the main clinical manifestations. The reasonable treatment for congenital common bile duct cyst is complete removal of the cyst and Roux-en-Y anastomosis of the common hepatic duct and jejunum to prevent the cyst from becoming cancerous. The Second Department of Hepatobiliary Surgery and Organ Transplantation Center of the First Affiliated Hospital of Kunming Medical University is experienced in the treatment of congenital cystic dilatation of bile ducts. Image of congenital cystic dilatation of bile ducts Expanded cyst seen during surgery Gallbladder and cyst after resection