Abstract：Objective：To observe the clinical effect of Dingchuan tang for chronic obstructive pulmonary disease(COPD) with phlegm-heat depressing the lung syndrome. Methods：A total of 100 cases of patients with COPD with phlegm-heat depressing the lung syndrome were randomly divided into the observation group and the control group，with 50 cases in each group. The control group was given routine treatment of western medicine including anti- inflammation，anti- infection and noninvasive ventilation，and the observation group was additionally treated with Dingchuan tang based on the treatment of the control group. The clinical effects in the two groups were observed and compared. Before and after treatment， the Chinese medicine syndrome scores， the blood gas indicators including partial pressure of carbon dioxide(PaCO2)， partial pressure of oxygen(PaO2) and oxygen saturation(SaO2)，and the levels of inflammatory factors including tumor necrosis factor- α(TNF-α)，interleukin-6(IL-6)，high-sensitivity C-reactive protein(hs-CRP) and procalcitonin(PCT) in the two groups were observed and compared. The mortality， complications， hospitalization time and incidence of adverse reactions in the two groups were compared. Results： The total effective rate was 94.00% in the observation group and 76.00% in the control group， the difference being significant(P＜0.05). Before treatment， there was no significant difference being found in the comparison of symptom scores including cough，expectoration and chest discomfort between the two groups(P＞0.05). After treatment，the above symptom scores in the two groups were decreased when compared with those before treatment(P＜ 0.05)，and the scores in the observation group were lower than those in the control group(P＜0.05). Before treatment，there was no significant difference being found in the comparison of levels of PaO2，PaCO2 and SaO2 between the two groups(P＞ 0.05). After treatment， the levels of PaO2 and SaO2 in the two groups were increased when compared with those before treatment(P＜0.05)，and PaCO2 level was decreased(P＜0.05)；the improvement of the indexes in the observation group was more significant than that in the control group(P＜0.05). Before treatment，there was no significant difference being found in the comparison of levels of TNF-ɑ，IL-6，hs-CRP and PCT between the two groups(P＞0.05). After treatment，the above levels in the two groups were decreased when compared with those before treatment(P＜0.05)， and the levels in the observation group were lower than those in the control group(P＜0.05). The mortality and incidence of complications in the observation group were lower than those in the control group(P＜0.05)， and the hospitalization time was shorter(P＜0.05). During treatment，there was no serious adverse reactions in the two groups. Conclusion：Dingchuan tang has a significant curative effect in treating COPD with phlegm- heat depressing the lung syndrome， and can effectively relieve clinical symptoms， regulate blood gas indicators and reduce inflammatory responses， so as to reduce mortality and incidence of complications，and shorten hospitalization time，with good medication safety.