Objective To evaluate the CT values in diagnosis of renal tuberculosis. Methods 26 cases were collected , the CT findings of renal tuberculosis were analysed and compared with the data of operation-pathology and clinical followed up. Results Of 26 cases, 22 cases diagnosed by CT as renal tuberculosis of one side were confirmed by operation-pathology but one (pseudaneurysm). Bilateral renal tuberculosis and renal cysts were diagnosed in 2 cases respectively by CT, while these 4 cases were confirmed as tuberculosis by other auxiliary checking methods and followed-up. The multiple tuberculoses cavities appeared as a petal-shape low-density area and other untypical signs on CT. The single cavity only showed as a low-density area should be distinguished with cystonephrosis. At early renal tuberculosis, a great quantity of effusion beneath the perinephrium was the only sign on CT.Conclusion CT scan has a special value for diagnosis renal tuberculosis. Typical renal tuberculosis can be made closely combining with the clinical information.