Abstract: Results :: To evaluate the significance of the variation of hepatic biliary confluence in the treatment of hilar cholangiocarcinoma. Methods : Patients with hilar cholangiocarcinoma treated in our hospital from January 2002 to March 2007 underwent magnetic resonance cholangiopancreatography (MRCP) examination. Twenty-four patients had variations of hepatic biliary confluence, including 16 patients who had potential for successful resection and underwent surgery. The clinical data of these 16 patients were retrospectively analyzed. Results : The variations of hepatic biliary confluence showed by preoperative MRCP examination in the 16 patients were supported by observations during surgery. The accuracy of MRCP in determining the type of variation was 100%. The right posterior duct fusing with the left hepatic duct was seen in 7 patients (43.8%), theso-called“trident confluence”was seen in 5 patients (31.3%), the right posterior duct directly fusing with thecommon bile duct was observed in 2 patients (12.5%), and the right anterior duct fusing with the left hepaticduct occurred in 2 patients (12.5%). Surgical resection was conducted in 9 patients (56.3%), of which 5 patients (31.3%) had R0 resection, 3 patients (18.8%) had R1 resection and 1 patient (6.3%) had R2 resection.Two patients (12.5%) suffered from postoperative complications and 1 died of biliary leakage. Conclusion :Hepatic biliary confluence is very common in hilar cholangiocarcinoma, and preoperative MRCP is an effective way to detect these variations. Some variations are beneficial and suitable surgical procedures can increase the resection rate of some hilar cholangiocarcinomas, especially Bismuth type Ⅲ-Ⅳ. Some variationsare helpful for surgeons who need to select an appropriate method of biliary-enteric anastomosis while avoiding injury of the bile duct during surgery.