Abstract: Objective: To study the feature of CT in primary ureteral carcinoma,to evaluate the diagnostic value of 64 multi-detector helical CT Urography in primary ureteral carcinoma.Methods: The CTU finding of primary ureteral carcinoma were analysed in 48 cases.The data was transmitted to ADW4.2 workstation,and reconstructed by MPR,CPR,VR,VE and generally analyzed with original axial images.Results: Of 48 primary ureteral carcinoma cases,5 cases are located in upper segment of the ureter,12 cases in middle segment,24 cases in lower segment and multiple is 7 cases.28 cases presented urinary obstruction,distention and hydronephrosis.Conclusion: The location,the shape,the spectrum of primary ureter carcinoma and change of surrounding tissue were clear in 64-MDCTU,is reliable and accurate in evaluating tumor,gradually become one of the first modality diagnose in primary ureteral carcinoma.