The following studies were made to establish a procedure for successful selective endoscopic retrograde cholangiography (ERC): 1) 787 cases of ERC performed in the past five years were divided into three groups. The first period was devoted to establishing the position of the patient most suitable to successful cholangiography. The second period was used to evaluate the validity of antispasmodics for successful cholangiography. The third period was devoted to making use of the knowledge obtained by anatomical studies reported in the previous paper. The success rate of selective cholangiography was 70.8 percent in the first period, 82.4 percent in the second period and 90.8 percent in the third period. This remarkable improvement in success rate indicates the importance of the use of anti-COMT drug and the improved cannulation resulting from anatomical evaluation. 2) 194 cases in the third period were analysed to establish the factors concerned with a success rate. Important factors included the type of the major papilla and orifice, swelling of the major papilla, site, direction, depth, and number of cannulation, positioning of the patient, the use of antispasmodics, and the skill of the endoscopist. As a result, several ways of cannulation for a successful selective ERC were established according to the type of major papilla and orifice and the presence or absence of swelling of the major papilla.