Objective To investigate the clinical significance of combined detection of inflammatory indicators in differential diagnosis of bacterial and viral pneumonia.Methods The 289 cases of bacterial pneumonia and 68 cases of viral pneumonia diagnosed in Jiading District Central Hospital Affiliated to Shanghai Medical College of Health from February 2020 to July 2023 were selected,and other 20 healthy individuals were included as control group.The levels of procalcitonin(PCT),interleukin-6(IL-6)and C-reactive protein(CRP)were detected,and the differences in levels of above indicators among three groups were compared.Receiver operator characteristic(ROC)curve was plotted,area under ROC curve(AUC)was calculated,and the clinical value of inflammatory markers in auxiliary diagnosis of bacterial and viral pneumonia was analyzed.Results The levels of PCT,IL-6 and CRP in bacterial pneumonia group were higher than those in viral pneumonia group[PCT(μg/L):0.14(0.05,0.49)vs.0.03(0.02,0.06);IL-6(ng/L):13.68(5.34,37.85)vs.6.00(3.23,9.45);CRP(mg/L):36.86(10.38,92.02)vs.3.58(0.58,10.61);all P<0.05].In distinguishing bacterial pneumonia from viral pneumonia,the AUC of PCT,IL-6 and CRP were 0.783[95%confidence interval(95%CI)was 0.726-0.841],0.705(95%CI was 0.640-0.769)and 0.816(95%CI was 0.765-0.867),respectively.Conclusion PCT,IL-6 and CRP have high efficacies in distinguishing bacterial pneumonia from viral pneumonia,which is of great significance for disease diagnosis.