Objective：To study the clinical significance of procalcitonin（PCT） in the diagnosis of urinary sepsis. Methods：Totally 41 patients with urinary sepsis and 79 patients with urinary tract infection were included in the study. The levels of PCT，hypersensitive C-reactive protein（hs-CRP），white blood cells（WBC） and neutrophil levels were detected in both groups. Receive operating characteristic（ROC） curve was drawn to evaluate the ability of PCT and related inflammatory parameters in assessing risk factors in patients with urinary sepsis. The correlation between PCT and hs-CRP，WBC and neutrophil was analyzed． Results：Compared with those of patients with urinary tract infection ，the levels of PCT（μg/L），hs-CRP（mg/L），WBC（×109/L） and neutrophil（×109/L） were signifi－cantly higher（PCT：3.113±1.953 vs. 0.057±0.0550，hs-CRP：18.82±15.460 vs. 7.440±14.52，WBC：12.860±4.002 vs. 8.15±4.63，neutrophil：90.335±3.975 vs. 74.30±15.40），with statistical significances（all P<0.05）. ROC curve displayed that area under the curve（AUC） of PCT was 1，higher than those of hs-CRP，WBC and neutrophils（0.813，0.875，0.984，respectively）. When PCT was 2.000 μg/L，the sensitivity was 90.2％ and specificity was 100％，better than those of other traditional markers of inflammation． Bi－variate correlation analysis showed that positive correlation was found between PCT and WBC and neutrophil（rs=0.609，P=0.000；rs=0.057，P=0.000） and there was correlation between PCT and hs-CRP（rs=0.213，P=0.020）． Conclusion：Serum PCT is a reliable mea－surement for the early diagnosis of urinary sepsis with high sensitivity and specificity and it is conducive to the early diagnosis and treatment of urinary sepsis.