Abstract： Objective： To observe the clinical effect of modified Qianjin Weijing tang assisting thymosin α1 for ICU patients with severe pneumonia complicated with G- bacteria infections，and to analyze its effect on atrial natriuretic peptide (ANP) and N-terminal pro-B-type natriuretic peptide(NT-proBNP) in plasma. Methods：A total of 100 cases of ICU patients with severe pneumonia complicated with G- bacteria infections were randomly divided into the observation group and the control group，50 cases in each group. The control group was treated with thymosin α1，and the observation group was additionally treated with modified Qianjin Weijing tang based on the treatment of the control group. The differences in clinical effect，inflammatory state and related indexes of heart injuries between the two groups were compared. Results：The total effective rate was 92.0% in the observation group，higher than that of 72.0% in the control group，the difference being significant(P＜0.05). Before treatment，there was no significant difference being found in the comparison of the levels of C-reactive protein(CRP)，interleukin-6(IL-6) and tumor necrosis factor-α(TNF-α) between the two groups(P＞0.05)；after treatment， the inflammatory factors in the two groups were decreased， and the decrease in the observation group was larger than that in the control group， the difference being significant(P＜0.05). The levels of ANP and NT- proBNP in the observation group were lower than those in the control group， the difference being significant(P＜0.05). Conclusion： Modified Qianjin Weijing tang assisting thymosin α1 has significant clinical effect in treating ICU patients with severe pneumonia complicated with G- bacteria infections， which can effectively inhibit inflammatory responses and improve immune function.