[en] A retrospectively study was performed to find any indicator to predict the difficulty of percutaneous transhepatic biliary drainage(PTBD) before the procedure and to evaluate correlationship between the chronological change of fluoroscopic time and the operator's experience. The materials included the consecutive 138 cases of PTBD of 120 patients with obstructive jaundice. Under the presumption that the difficultly of procedure would be reflected on fluoroscopic time, the correlation between fluoroscopic time and eight factors(i.e. ; sex, age, disease, approach, degree of IHD dilatation, total bilirubin, alkaline phosphatase, and operator) were analysed. Also chronological change of fluoroscopic time in three operators, who performed more than 25 procedures, were evaluated. Statistically significant factors were operator (p=0.000), sex (p=0.028), approach (p=0.048), and total bilirubin (p=0.021). Good correlation between the chronological change of fluoroscopic time and the operator's experience was found. The significant factors could be used as an indicator to predict the difficulty before PTBD procedure. The chronological change of fluoroscopic time could be used as an indirect estimate in the stabilization of the operator technique