Choledochal cysts are characterized by single or multiple cystic dilatations of the intrahepatic and / or extrahepatic biliary ducts. The typical presentation of this condition is non-specific. Clinicians must have a high clinical suspicion of choledochal cysts while investigating patients with jaundice, abdominal pain, and abdominal mass. There are multiple classifications for choledochal cysts . The Todani classification system is the most widely used in clinical practice. Based on clinical practice and thinking, we established a new “three regions and five types” classification system on the basis of Todani classification to guide clinical work, but further verification is needed. Surgery is the mainstay of treatment for choledochal cysts and the approach depends on the cyst type and the extent of hepatobiliary pathology. The principles of treatment include complete excision of the cyst and restoration of biliary-intestinal continuity. In view of the risk of biliary malignancy continues to be high after surgery, long-term follow-up is strongly recommended.