To evaluate the diagnostic value of MRCP in finding positions and causes of obstructive jaundice.Fourty-two patients with obstructive jaundice received MRCP examination. All patients were finally onfirmed operatively.The correct diagnostic rate of finding obstructive positions in MRCP was 100% and the correct rate of finding obstructive causes 78.57%. MRCP combined with MRI raised the accuracy of diagnosis of obstructive causes. (90.48%). All pathogenic changes have their own characteristics.MRCP in diagnosing obstructive jaundice is quite effective and safe because of its clear pictures without use of contrast medium and no complications.