The diagnosis and treatment of intrahepatic stone was considered difficult previously. We report the result of fibercholangioscope on diagnosis and treatment of intrahepatic stone and discuss the possibilitys of its clinical uses. In a period of 5 years, we carried out operative f iberch-olangioscopic examinations on 214 patients (Table 1) Almost all cases were cholelithiasis and 42 of them, (20%) were intrahepatic stones. Most of the patients with intrahepatic stone were refered for operation by the first time, but 16 cases, (38%) were for reoperation. We classified "intrahepatic stone" with 5 types according to the site of narrowing of the biliary tract; It is convenient for selecting the operative methods, and studying of the cause and its prognosis. (Table 2) We have succeeded in removing the residual stone in most cases of type I (no narrowing) or type II (narrowing at duodenal papilla and lower portion of choledochus) of intrahepatic stones. However it is difficult the remove the stone in type III, IV and V. (narrowing at hepatic hilus and intrahepatic duct) (Table 3) The treatment of intrahepatic stone is not only to remove the stone completly but also to ream the narrowing of the biliary duct to decrease pressure and to drain the biliary system. Restenosis occured at the anastomotic portion of choledochojejunostomy in some cases for example. We tried to incise the narrowing by electric snare under fiber cholangioscope. Moreover, we gained good result by carry-ing out PTC-drainage and "endoscopic choledochal catheterization for drainage". The development of f ibercholangioscope makes it possible not only to remove stone easily bt also the diagnosis and to treatment of intrahepatic stone hitherto it is considered difficult.