Abstract: [Abstract] Objective To investigate the clinical application of urography by 320 row of dynamic volume CT for urinary tract obstruction. Methods 64 patients with urinary symptoms received urography by 320 row dynamic volume CT. All pathological changes through surgery or conventional pathology inspection confirmation, including ureteral calculus( n= 51)，urinary tract neoplasms(n= 4)，urinary tuberculosis ( n= 4). Results CTU can clearly demonstrate the location of urinary tract obstruction，morphology and the relationship with the surrounding tissue, so as to make the qualitative diagnosis.Conclusion CTU is a new and safe imaging technique with excellent accuracy in the diagnosis of urinary tract obstruction，it has an important clinical value.

Key words: [Key words]CT of 320 slice, Dynamic volume, CT urograghy, Ureteral obstruction