Abstract: OBJECTIVE To explore the value of procalcitonin in diagnosis of bacterial infections so as to provide guidance for clinical diagnosis and treatment. METHODS A total of 97 patients with acute infections who were treated in the hospital from Feb 2012 to Dec 2014 were recruited as the study objects, 45 patients with bacterial infections were assigned as the observation group, and 52 patients with non-bacterial infections were set as the control group.The level of procalcitonin was determined for the patients, the indicators and distribution of inflammations were observed by using the procalcitonin, the sensitivity and specificity in the diagnosis were analyzed, and the statistical analysis of data was performed with the use of SPSS18.0 software. RESULTS There were 3 patients with level of procalcitonin less than 0.5 ng/ml in the observation group and 43 patients in the control group; there were 26 patients with level of procalcitonin varying from 0.5 to 2.0 ng/ml in the observation group and 8 patients in the control group; there were 16 patients with level of procalcitonin more than 2.0 ng/ml in the observation group and 1 patient in the control group, with statistical significance (P＜0.05).The detection of sensitivity and specificity of the inflammatory indicators indicated that among the 45 patients with bacterial infections, there were 40 patients whose total white blood cell counts reached the critical value, 37 patients whose neutrophils ratio reached the critical value, and 26 patients whose PCT level reached the critical value; among the 52 patients with non-bacterial infections, there were 23 patients whose total white blood cell counts reached the critical value, 20 patients whose neutrophils ratio reached the critical value, and 9 patients whose PCT level reached the critical value.The sensitivity and specificity of the PCT were higher than those of the neutrophils ratio and total while blood cell counts. CONCLUSION The procalcitonin has high specificity and sensitivity for the patients with bacterial infections, and it has great clinical significance in the diagnosis of the patients with bacterial infections.