The commonly used B-type ultrasound cystography, SPECT (single proton elected compute rized tomography), and recently developed spiral CT continuous scan followed by 3D reconstruction and simulated endoscopy (virtural intra lumina lendoscopy, VIE), magnetic resonance cholangio-pancreatography (MRCP) can make a more definite diagnosis of congenital common bile duct cyst. (magnetic resonance cholone-giopancreatography, MRCP), can make a clear diagnosis of congenital common bile duct cysts. Combined with clinical manifestations such as abdominal pain, mass and jaundice, the diagnosis is not difficult.