In normal physiological anatomy

common bile duct opens in the major papilla and does not communicate with the minor papilla directly. There is little chance to cannulate biliary system via the minor papilla. There was no report of trans-minor papilla biliary drainage in the literature. We presented a case with malignant obstructive jaundice that underwent trans-minor papilla biliary drainage. A 5F super slim nasobiliary tube was inserted into common bile duct successfully through minor papilla during endoscopic retrograde cholangio-pancreatography （ERCP）. The patient did not complain abdominal pain or any discomfort after procedure. Biliary drainage was effective （500-800 ml per day）. The patient’s jaundice relieved significantly during follow-up.