Objective To study the pathogenic factors of obstructive jaundice, improve the level of CT diagnosis.Methods in our hospital from 2009 February to 2013 August 55 cases of obstructive jaundice patients were confirmed by operation and pathology or after treatment, the CT features were analysedResults 13 cases of bile duct stones, inflammation in 5 cases, 8 cases of bile duct carcinoma, 1 cases of liver cancer, hepatic, pancreatic rear lymph node metastasis carcinoma 1 cases, 16 cases of carcinoma of head of pancreas, 11 ampulary cancerConclusion CT scan can clearly without obstruction, determining the site of obstruction, further qualitative diagnosis.