【Abstract】 Objective To compare the clinical value of procalcitonin (PCT) and other inflammatory markers in the diagnosis of neonatal and childhood infectious diseases. Methods A retrospective analysis of 490 patients admitted to the hospital from July 2014 to January 2016 was analyzed. According to the American college of chest physicians and critical care medicine meeting standards (ACCP/SCCM) diagnosis of infection and infection complications, the patients were divided into local infection group (421 cases) and systemic infection (69 cases). The PCT and other inflammatory indexes Creactive protein (CRP), the WBC, neutrophil percentage (NEU %) and prealbumin (PA) and the testing results of microbial cultures were observed to assess PCT in infectious disease severity classification and prediction of clinical value. Results In neonates, the PCT value was statistically significant in the differentiation of local infection group and systemic infection group (P＜005). PCT increased with the severity of infection. As the critical value of PCT＞05 ng/ml, and the CRP, WBC, NEU %, microbial cultivation in the sensitivity of the diagnosis of bacterial infection, specific degree, positive predictive value (higher were 1441%, 1441%, 1250%), PCT values of the indicators were 2314%, 25% and 2314%, respectively. The difference was statistically significant (P＜005). There was no statistically significant difference between the grampositive group and the gram negative group (P BBB 0. 05) in the 98 samples of the positive microorganism culture. Conclusion PCT in distinguish between infection type has a certain value, compared the CRP, WBC, NEU %, microbial cultivation. The PCT values in the diagnosis of newborn babies and children's infectious diseases and to predict its severity is more meaningful, but the PCT value cannot distinguish between G + bacteria and Gbacteria.