Abstract： Objective： To observe the clinical effect of Bufei Huayu Tongluo tang combined with alteplase for chronic pulmonary embolism and its effect on the lung function， arterial blood gas indexes and coagulation function of patients. Methods： A total of 62 cases of patients with chronic pulmonary embolism were selected and randomly divided into the observation group and the control group，31 cases in each group. The control group was given injection of alteplase，and the observation group was additionally treated with Bufei Huayu Tongluo tang based on the treatment of the control group. The clinical effect was compared between the two groups. Indexes of the lung function， arterial blood gas analysis and coagulation function before and after treatment were compared between the two groups. Results： The total effective rate was 90.32% in the observation group，higher than that of 67.74% in the control group，the difference being significant(P＜ 0.05). After treatment，percentage of the estimated forced expiratory volume in the first second(FEV1) and forced expiratory volume in first second/forced vital capacity(FEV1/FVC)， as well as levels of partial pressure of oxygen(PaO2) and partial pressure of carbon dioxide(PaCO2) in the two groups were improved when compared with those before treatment(P＜0.05)； the improvement of the four indexes above in the observation group was more significant than that in the control group(P＜ 0.05). After treatment，prothrombin time(PT) in the two groups was prolonged when compared with that before treatment(P＜ 0.05)， and PT in the observation group was longer than that in the control group(P＜0.05). After treatment， levels of fibrinogen(FIB) and blood platelet count(BPC) in the two groups were increased when compared with those before treatment (P＜0.05)，and the two levels in the observation group were higher than those in the control group(P＜0.05). Conclusion：In the treatment of chronic pulmonary embolism，the therapy of Bufei Huayu Tongluo tang combined with alteplase can enhance the clinical effect and effectively improve the lung function，indexes of arterial blood gas analysis and coagulation function.