Abstract: Objective　To investigate the changes of urine conductivity in healthy subjects and patients with urinary stones and the clinical application of urine conductivity.  Methods　A total of 436 healthy subjects and 348 patients with kidney and ureter stones diagnosed by ultrasound were enrolled. UF1000i automatic urine sediment analyzer was used to determine urine conductivity.  Results　Random urine conductivity showed normal distribution in healthy subjects. Urine conductivities of healthy subjects who were older than 40 years old were lower than those of subjects who were 40 years old or younger (P＜ 0.001). Urine conductivities of patients with kidney and ureter stones were lower than those of healthy subjects (P＜ 0.001). There was no difference in urine conductivities between patients with different-size stones. Receiver operating characteristic (ROC) curves were drawn by making urine conductivity as a diagnostic test of stone disease，and the areas under ROC curves were＜0.3.  Conclusions　Urine conductivities in patients with urinary stones are lower than those in healthy subjects，and the size of urinary stone does not influence the urine conductivity. Urine conductivity can not be used as a diagnostic test of urinary stones，but can be used as a screening experiment to remind doctors doing ultrasound to detect urinary stones combined with the other urine parameters.

Key words: Urine, Conductivity, Urinary stone, Automatic urine sediment analyzer