Objective To investigate the changes of white blood cell(WBC),neutrophil(NEU),glucose(GLU) and C-reaction protein(CRP) in the patients with severe pneumonia and their clinical significance.Methods 59 patients with severe pneumonia and 60 patients with common pneumonia were selected for testing WBC,NEU,GLU,CRP,with healthy crowd undergoing physical examination as the control group.Results GLU and CRP concentrations in the severe pneumonia and common pneumonia groups were higher than those in the control group(P0.01).GLU and CRP concentrations had no statistical difference between the common pneumonia group and the control group.NEU had the statistical differences among the three groups(P0.01).WBC in the severe pneumonia and common pneumonia groups had statistical difference compared to the control group(P0.05),while WBC between the common pneumonia and severe pneumonia groups had no statistical difference(P0.05).Conclusion Monitoring WBC,NEU,CRP and GLU contributes to judge the severity of disease condition and prognosis.