From 1978 to Dec. 1991, 50 cases of dilatation of the extrahepatic biliary duct in children were treated. They were classified as: cystic dilatation in 34 cases, arid fusiform dilatation in 16 cases. Types of reconstruction of the extrahepatic biliary duct included: excision of cystic dilatation and Rorx-en-Y hepatoductojejunostomy in 25 cases, and interposition of jejunum and hepatoductoduodenostomy in 9 eases. for those cases having fusiform dilatation, interposition of jejunum and hepatoductoduodenostomy，cases and Rorx-en-Y-hepatoductojejunostmy 5 cases.The follow-up period averajed 6.5 years. Forty nine patients were recoverwd from the teatment and 1 patient died.