Purpose:To evaluate the effect of 3DRT for malignant biliary obstruction and to find a more effective method of treatment.Methods:Form October 1998 to September 2000,35 patients with malignant biliary obstruction ,3-4 Gy of 5 fractions a week to total doses from 38 to 48 Gy.Results:All cases completed radiation. CR rates were 24%,PR rates were 63%,the overal response rate (CR+PR) was 87%. A significant decrease of bilirubin levels was observed in 29 patients,no serious complications occured. 1-2 year survival rates were 70% and 21%.Conclusions:3DRT is well tolerated in most patients with malignant biliary obstruction,its effect is better than the conventional radiation and it is a more effective treatment for the malignant biliary obstruction.