Abstract：Objective：To observe the clinical efficacy of Yupingfeng granules assisted tiotropium bromide in the treatment of stable chronic obstructive pulmonary disease and its influence on lung function. Methods：82 patients with stable chronic obstructive pulmonary disease were taken as subjects and divided into observation group with 42 cases and control group with 40 cases by random number table. After admission，the two groups were given conventional symptomatic treatment. On this basis， the control group was treated with tiotropium bromide， and the observation group was treated with Yupingfeng granules on the basis of the control group. After the course of treatment，the clinical efficacy and pulmonary function index changes of the two groups were evaluated. Results：The total effective rate of treatment in the observation group(90.48%) was better than that of the control group(70.00% ) (P＜0.05). The scores of TCM syndromes and the number of acute exacerbations before treatment in the two groups were not statistically different(P＞0.05)；the scores of TCM syndromes and the number of acute exacerbations in the two groups were significantly reduced after treatment，and the observation group was lower than the control group(P＜0.05). There was no significant difference in lung function(FEV1/FVC， FEV1% PRDE) between the two groups before treatment(P＞0.05)；the lung function indexes of the two groups were significantly improved after treatment，and the observation group was higher than the control group(P＜0.05). IgA，IgE，IgM，and IgG levels in the two groups before treatment were not statistically different(P＞0.05)； IgA， IgM， and IgG levels in the observation group after treatment were higher than those in the control group，and IgE levels were lower than before treatment(P＜0.05). The content of IgA，IgM，and IgG in the control group after treatment was not statistically significant(P＞0.05)，and the content of IgE was lower than before treatment(P＜0.05). Conclusion：For patients with stable COPD，taking Yupingfeng granules to assist tiotropium bromide treatment is beneficial to improve the clinical efficacy， relieve clinical symptoms， reduce the number of acute exacerbations，improve lung function，and regulate immune function.