Abstract: Objective: To evaluate clinical application of multislices CT angiography(CTA) combining with CT urography(CTU) in the diagnosis of urinary system diseases. Methods: 58 patients with urinary system diseases had CT plain scan, renal dual-phase enhanced scan and delayed urinary system scan. The scan data were sent to post-processing workstation to get two-dimensionally and three-dimensionally reconstructed CTA combining with CTU images, such as maximum intensity project(MIP), multiplannar reconstruction(MPR), curved projection reconstruction(CPR) and volume rendering(VR). Results: Among 58 patients, there were 28 cases of calculi in urinary system, 6 cases of renal cancer, 4 cases of renal pelvis carcinoma, 2 cases of ureter carcinoma, 3 cases of bladder carcinoma which invaded ureter, 11 cases of external ureteral stricture, 4 cases of congenital renal dysplasia. 42 cases were confirmed by surgery pathology and 16 cases were proved by clinical examination. CTA combining with CTU can distinctly show lesions in the relationship with the surrounding tissues, organs and blood vessels. Conclusion: CTA combining with CTU can display the relationship between the urinary system and adjoining blood vessels by two-dimensionally and three-dimensionally reconstructed with post-processing technique. It is a very important evidence for clinic diagnosis and treatment plan in urinary system diseases,and should be used in routinely clinical application.