Objective To investigate the clinical characteristics of congenital cholangiectasis,the classification of choledochectasia and its complications. Methods Sixty-eight patients with congenital cholangiectasis admitted to Nankai hospital of Tianjin from Jan. 2000 to Dec. 2009 were retrospectively studied. The patients were classified using Todani method. The clinical presentation,complications and development were compared among patients with different types. Results In 68patients, type Ⅰ , Ⅳa and Ⅳb were accounted for 47. 1%, 35.3%, 17.6%,respectively. Wheraes type Ⅱ , Ⅲ and Ⅴ were not found. The complications included cholecystitis (67.6%) and bile duct stone (70. 6%). Biliary stricture and gallbladder atrophy were accounted for 26.5% and 17.6%,respectively. Pancreatitis was found in 8.8% patients, biliary cirrhosis in 5.9% patients,carcinogenesis in 23.5 % patients, fatty liver steatosis in 11.8 % patients, cholecystic polyps in 17.6 %patients, slight spleen enlargement in 14.7% patients, hepatic cyst in 8. 8% patients, renal cyst in 2.9% patients. Conclusions Tyep Ⅰ is commonly found in congenital cholangiectasis, and the next is the type of Ⅳa, but no type of Ⅱ , Ⅲ or Ⅴ is found. The common complications are cholecystitis and bile duct stone. Carcinogenesis is found in 25 % patients.