[OBJECTIVE]:To study the functional mechanism of Pingchuanning Decoction in treatment of airway remodeling in asthmatic rats.[METHODS]:Eighty healthy Wistar male rats were randomized into eight groups (n=10 rats each):Normal group,Asthma model group,Dexamethasone group,Guilong Kechuanning group,Xiaoqinglong Decoction group,and Pingchuanning Decoction low-,middle-,and high-dose groups.The rats of all but the Normal group were made into asthma models through intraperitoneal injection and aerosol inhalation of ovalbumin.All treatments were administered at the first stimulation of asthma onset (third week of modeling),and the rats were killed after stimulating asthma attacks for 4 weeks.The general conditions of rats and pathomorphological changes of the lung tissues were observed.The expression of nerve growth factor (NGF) of the lung tissues was measured with immunohistochemicalmethods,and the content of Clara cell secretory protein (CCSP) mRNA was determined with RT-PCR.[RESULTS]:Compared with the Normal group,the contents of NGF and CCSP mRNA in the lung tissues of the Model group were significantly changed (P＜0.01).Compared with the Model group,the indices of Pingchuanning Decoction and other treatment groups were improved to some extent (P＜0.05 or P＜0.01).[CONCLUSIONS]:Pathological changes of airway inflammation and remodeling were present in these rat asthma models.Pingchuanning Decoction had an intervention effect on these experimental models.Its functional mechanism may be related to multiple factors,including alleviation of airway inflammation,relief of bronchial smooth muscle spasm,and inhibition of airway remodeling.