Abstract: Objective To investigate the clinical effect of shengjiang white tiger decoction combined with thymosin α1 on the treatment of elderly patients with severe pneumonia.Methods A total of 64 elderly patients with severe pneumonia were collected and randomly divided into observation group and control group,32 cases in each group.All the patients were treated with routine anti infection therapy,cough and asthma therapy,nutritional support and other conventional treatment.The control group was given subcutaneous injection of thymosin o1,and the observation group was treated with additional shengjiang white tiger decotion on the basis of control group.After two weeks continuous treatment,the immune cells (CD3 +,CD4 +,CD8 +,CD4 +/CD8 +) and serum inflammatory markers (WBC,CRP and IL-6) as well as the effect and the incidence rate of adverse reactions,hospitalization time,medical cost were compared between two groups.Results After treatment,the CD3 +,CD4 +,CD8 +,CD4 +/CD8 +,WBC,CRP,IL-6 improved significantly (P ＜ 0.05).CD3 + and CD4 + in the observation group were significantly higher than the control group,while WBC,CRP and IL-6 were significantly lower than the control group (P ＜ 0.05).Patients in both groups had no obvious adverse reactions.The excellent rate of observation group was 65.62％,which was significantly higher than 40.62％ of the control group (P ＜ 0.05).In the observation group,hospitalization time and medical costs were significantly lower than the control group (P ＜ 0.05).Conclusion Shengjiang white tiger decoction combined with thymosin α1 is effective and safe in the treatment of elderly patients with severe pneumonia.