To investigate the common causes and differential diagnosis of malignant jaundice, we reviewed 903 cases with obstructive jaundice in PUMC hospital in recent 16 years. 383 of them were malignant jaundice (42.4%). The most common origin of malignant jaundice was carcinoma of the pancreatic head with 198 patients (51.7%), and carcinoma of the ampulla Vater with 94 cases (24.5%) and carcinoma of the extrahepatic bile duct with 71 cases (5.2%). The clinical symptoms and signs were not much helpful to the differentiation of malignant jaundice. No specific early signs were found to the malignant jaundice, but most of the patients felt epigastric distension and distress, anorexia, loss of body weight and fatigue before jaundice appeared. More than one third patients had discontinuous fever. The imaging investigation had decisive roles in the diagnosis and differential diagnosis of the malignant jaundice. The positive rate of diagnosis in sonography was 95.5%, but the correct rate only 85.0% (P < 0.05). We regard that sonography might be the first imaging examination for the malignant jaundice and clue for further investigation. ERCP can clearly reveal the papilla, biliary and pancreatic ducts with high positive rate (97.7%) and correct rate (95.1%). PTC was only used in those patients who had the contraindications to ERCP or the cannulation of ERCP was not successful. The positive rate of PTC was 95.8% in the cases with extrahepatic cholangiocarcinoma. The combination of ERCP and PTC could determine the position and extent of extrahepatic cholangiocarcinoma.(ABSTRACT TRUNCATED AT 250 WORDS)