The CT findings and preoperative CT staging accuracy of 14 renal transitional cell carcinoma were discussed and were correlated with operative and pathological findings. Each seven cases were occured in right and left kidndy. Upper ople calyx and pelvis were the most common site of tumor location. The multiplicity of lesions in the ipsilateral ureter and/or bladder were observed in 3 cases(21.4%). we could accurately diagnose the lesion in all cases by CT. The attenuation value of the tumor was 31-45 HU in prenehance scan and it enhanced upto 56-80HU after injection of contrast media. Delayed enhancement of the renal parenchyme and parenchyaml thinning around the periphery of the tumor were observed in 7 cases. Those findings were also observed in stage A, therefore those findings were from compression effect by the tumor than true tumor invasion. The accuracy of CT staging was 75% and only 3 cases were misstaged. Two of the 3 cases were overstaged due to associated parenchymal infection. So CT scan is valuable study for diagnosis and staging of the renal pevis tumor and can play definite role for determination of treatment method and prognosis.