Abstract:To evaluate the value of endoscopic ultrasonography (EUS) in the diagnosis of bile duct stones.?Methods?353 suspected cholangiolithiasis patients with endoscopic ultrasonography from January 2014 to May 2017 were included. Results of ERCP, surgery or follow-up as the gold standards, then evaluate the value of EUS in diagnosis of bile duct stones, and compared with TUS, CT, MRCP.?Results?In 353 patients, 176 cases were diagnosed with bile duct stones by EUS, of which 2 cases were not seen bile duct stones by ERCP. 17 patients proved to be stones in the 177 patients with EUS negative. The diagnostic sensitivity, specificity, positive predictive value, negative predictive value, Youden index, accuracy of EUS to bile duct stones were 91.1%, 98.8%, 98.9%, 90.4%, 89.9%, 94.6% respectively. Diagnostic efficacy of EUS were superior to TUS and CT in big biliary stones (>5?mm), small bile duct stones (≤?5 mm), Sediment-like bile duct stones, lower bile duct stones and upper bile duct stones. There was no statistical difference between EUS and MRCP (P?=?0.070) in big bile duct stones. EUS was superior to MRCP in small bile duct stones, sediment-like bile duct stones, lower bile duct stones and upper bile duct stones.?Conclusion?It has great clinical advantage using EUS to diagnose bile duct stone, and it can be used as an effective diagnostic method before invasive operation.