CT shows a mass in the ureter, which may be a danger sign and must be paid attention to, and timely medical treatment to find out the nature of the mass and deal with it accordingly. CT examination shows a mass in ureter, which may be benign or malignant. If the patient combines with painless hematuria, hydronephrosis, rapid progress of the mass, urinary tract infection and malignant symptoms, it may be a danger signal of malignancy, and the patient needs to be on high alert for the possibility of cancer, and should communicate with the supervising physician as soon as possible to do further examination to find out the nature of the mass and deal with it accordingly. Most of the ureteral cancers are uroepithelial carcinoma, followed by squamous carcinoma and adenocarcinoma, etc. The main clinical manifestations are painless hematuria throughout the whole course. Most of the patients have already undergone infiltration of muscular layer or surrounding tissues when they are found, and a few patients are found by chance through physical examination. Different pathological types and different stages of ureteral cancer patients vary greatly and need to be analyzed with specific situations. In conclusion, if CT shows that a mass is found in the ureter, it should be promptly consulted and actively treated.