Abstract: Objective To study the effect of Bufei Yishen Huayu Decoction on airway function of chronic obstructive pulmonary disease (COPD) patients and its mechanism. Methods One hundred and sixty-six patients with stable COPD were randomly divided into two groups, each group 83 cases. The control group was treated with salbutamol and ipratropium bromide inhalation. The observation group was treated with Bufei Yishen Huayu Decoction based on the control group. After treatment, clinical symptoms, pulmonary function[FEV%, FEV1/FVC], serum TNF-α and TGF-β1, and clinical efficacy of two groups were compared. Those data were analyzed by SPSS soft to analyze the effect of Bufei Yishen Huayu Decoction on airway function of COPD patients and its mechanism. Results After treatment, the total effective rate of observation group was 92.77%, which was significantly higher than that of control group (77.11%, P<0.05). After treatment, clinical symptoms scores of two groups were significantly decreased (P<0.05), and the observation group was significantly lower than the control group (P<0.05). After treatment, FEV% and FEV1/FVC of two groups were significantly increased (P<0.05), and the observation group was significantly higher than the control group (P<0.05). After treatment, the TNF-α and TGF-β1 levels of observation group were significantly reduced (P<0.05), and lower than those of control group (P<0.05). Conclusion Bufei Yishen Huayu Decoction could significantly improve the clinical symptoms and pulmonary ventilation function of patients with stable COPD. The internal mechanism of airway remodeling may be related to reduce airway inflammation and reduce TGF-β1.