Abstract: Objective To investigate the significance of ultrasound examination in the diagnosis of bile duct carcinoma present in the portal area (where there is union of left hepatic duct, right hepatic duct and common hepatic duct) of porta hepatis.Methods Normal ultrasonic examination of hepato-biliary area was performed in patients with their full cooperation and consent.The blood vessels of portal area, route and distribution of bile ducts, size and boundary of tumor mass, dilatation of intrahepatic bile duct, condition of distal extrahepatic bile duct, and tissue composition around these structures were observed carefully along with their echo patterns.The abnormal images were recorded and co-analyzed with the results from CT, MRI, and surgery.Results Among the 54 cases that were found with bile duct carcinoma from ultrasound, 29 cases were confirmed from CT, MRI images and 25 cases were confirmed after surgery.Conclusion The direct and indirect ultrasonic findings of abnormal structures or masses in portal area have certain specificity and also have great diagnostic importance in deciding bile duct carcinoma.