Abstract： Objective： To observe the curative effect of Qingre Xuanfei tang combined with ulinastatin for severe pneumonia and its effect on inflammatory factors and immune function. Methods：A total of 150 cases of patients with severe pneumonia of phlegm- heat in the lung type were selected and divided into the control group and the observation group according to the random number table method，with 75 cases in each group. Both groups were given routine treatment；the control group was additionally given ulinastatin，and the observation group was additionally given Qingre Xuanfei tang based on the treatment of the control group. Both groups were treated for 10 days. Before and after treatment， the changes in clinical symptoms，disease conditions including the scores of Acute Physiology and Chronic Health EvaluationⅡ(APACHEⅡ)， Clinical Pulmonary Infection Score(CPIS) and Pneumonia Severity Index(PSI)，the levels of inflammatory factors including high mobility group protein B1(HMGB1)，procalcitonin(PCT) and white blood cell(WBC) as well as immune function including the levels of helper T cells(CD4+)，suppressor T cells(CD8+) and CD4+/CD8+ in the two groups were compared. During treatment， the incidences of adverse reactions in the two groups were observed. Results：After treatment，the scores of fever，phlegm congestion and panting in the two groups were decreased when compared with those before treatment，and the above three scores in the observation group were lower than those in the control group， differences being significant(P＜0.05). After treatment，the scores of APACHEⅡ，CPIS and PSI in the two groups were decreased when compared with those before treatment， and the above three scores in the observation group were lower than those in the control group， differences being significant(P＜0.05). After treatment，the levels of HMGB1，PCT and WBC in the two groups were decreased when compared with those before treatment， and the above three levels in the observation group were lower than those in the control group，differences being significant(P＜0.05). After treatment，the levels of CD4+ and CD4+/CD8+ in the two groups were increased when compared with those before treatment，and CD8+ levels were decreased；the levels of CD4+ and CD4+/ CD8 + in the observation group were higher than those in the control group， and CD8 + level was lower， differences being significant(P＜0.05). During treatment，the incidence of adverse reactions was 9.33% in the observation group，including one case of liver and kidney dysfunction，one case of rash，two cases of diarrhea，and three cases of nausea and vomiting；in the control group，the incidence of adverse reactions was 22.67%，including three cases of liver and kidney dysfunction， three cases of rash，five cases of diarrhea and six cases of nausea and vomiting. There was significant difference being found in the comparison of the incidences of adverse reactions between the two groups(P＜0.05). Conclusion： The therapy of Qingre Xuanfei tang combined with ulinastatin for severe pneumonia has a significant curative effect， and can delay the development of disease， reduce the levels of inflammatory factors and improve the body immunity， with high medication safety.