To observe the clinical curative effect of Modified Maxing Shigan Decoction in the treatment of severe pneumonia and its effects on lung function,the serum level of inflammatory cytokines,red blood cell distribution width,red blood cell volume and the level of HMGB1.Methods:A total of 146 patients with severe pneumonia treated in Xianyang Central Hospital from February 2016 to February 2017 were selected and divided into control group and observation group according to the random table method,with 73 cases in each group.The control group was given western medicine for anti-infection,relieving cough and eliminating phlegm,bringing down fever.The observation group was given Modified Maxing Shigan Decoction based on the same treatment of the control group.The clinical effect,pulmonary function,the level of serum inflammatory factors (WBC,PCT,CRP,TNF-α),prealbumin,RDW,MCV,HMGB1 of both groups were observed.Results:After treatment,the pulmonary function indicators (PImax,PEmax,MMF,PEF),prealbumin of two groups increased significantly (P<0.05),and the level of serum inflammatory cytokines (WBC,PCT,CRP,TNF-α),RDW,MCV,HMGB1 decreased obviously.The above indexes changed more obviously in the observation group.The differences were statistically significant (P<0.05).The total effective rate of the observation group was (91.41%) which was obviously higher than that of the control group (64.38%),and the difference was statistically significant (P<0.05).Conclusion:Modified Maxing Shigan Decoction in the treatment of severe pneumonia can improve lung function,reduce the level of serum inflammatory factors,prealbumin,HMGB1,red blood cell distribution width and red blood cell volume to improve the clinical therapeutic effect.