OBJECTIVE：To investigate inhibitory effects of Qing fei baoyu an capsule on airway inflammation in rats with chronic obstructive pulmonary disease （COPD），and its effects on NLRP 3 signaling pathway. METHODS ：Totally 60 SD male rats were randomly divided into blank control group ，model group ，dexamethasone group （positive control ，0.2 mg/kg），Qingfei baoyuan capsule high-dose ，medium-dose and low-dose groups （1 232.0，616.0，308.0 mg/kg），with 10 rats in each group. Except for blank control group ，other groups were fumigated for 28 days and given intratracheal dripping of lipopolysaccharide twice to induce COPD model. Since the 29th day after modeling ，blank control group and model group were given constant volume of normal saline intragastrically ，and administration groups were given related medicine intragastrically. The administration volume was 10 mL/kg，once a day ，for consecutive 28 days. After last administration ，the lung function was detected. The pathological changes of lung tissue were observed by HE staining. The content of interleukin- 1β（IL-1β）in bronchoalveolar lavage fluid （BALF）were detected by ELISA ，and the number of leukocytes was counted ；the expression of NLRP 3 and Cleaved caspase- 1 in lung tissue of rats were detected by Western blotting assay. RESULTS：Three，two，one，one and two rats died in model group， dexamethasone group ， Qingfei baoyuan capsule high-dose，medium-dose and low-dose groups ，respectively. Compared with blank control group ，FEV0.3/FVC of rats in # model group was significantly decreased （P＜0.01）. A large number of inflammatory cells infiltration we re found in the lung tissue ，and lung tissue lesion was obvious. The content of IL- 1β and white blood cell count in BALF，relative expression of NLRP3 and Cleaved caspase- 1 protein in lung tissue were increased significantly （P＜0.05 or P＜0.01）. Compared with model group，FEV0.3/FVC of administration groups were increased significantly （P＜0.05 or P＜0.01）；lung tissue lesion of them were improved to different extents. The content of IL- 1β and white cell count in BALF，relative expression of NLRP 3 protein（except for Qingfei baoyuan capsule low-dose group ）and Cleaved caspase- 1 protein（except for Qingfei baoyuan capsule medium-dose and low-dose groups ）in lung tissue were decreased significantly （P＜0.05 or P＜0.01）. CONCLUSIONS ：Qingfei baoyuan capsule can relieve lung tissue lesion and improve lung function in COPD model rats ，the effects of which may be associated with inhibiting inflammation reaction by inhibiting NLRP 3 signaling pathway.