By observing the effect of Taoren（Persicae Semen）on cough variant asthma（CVA）model rats，it discussed the effect and mechanism of Taoren（Persicae Semen）in relieving cough and asthma.

Smoke combined with ovalbumin（OVA）-aluminium hydroxide sensitisation and nebulisation of OVA sensitising solution method was used to establish a CVA rat model to evaluate the efficacy of Taoren（Persicae Semen）in relieving cough and calming asthma by observing the general morphology of the rats，determining the incubation period of cough，the number of coughs and lung function and observing the pathological changes in the lung tissues of the rats with the HE staining method. Masson staining was used to measure collagen deposition in rat lung tissues. HE staining was used to measure airway morphological parameters of bronchial tubes. Enzymelinked immunosorbent assay（ELISA）method was used to measure the levels of interferon-γ（IFN-γ），interleukin-4（IL-4），interleukin-5（IL-5），interleukin-13（IL-13），nerve growth factor（NGF）in rat bronchoalveolar lavage fluid（BALF），and immunohistochemistry method forα-smooth muscle actin（α-SMA）expression，to explore the mechanism of action of Taoren（Persicae Semen）in relieving cough and asthma.

After 2 weeks of continuous administration，compared with those of the CVA model group，the general morphology of rats in each dose group of Taoren（Persicae Semen）could be improved to different degrees. The body weight of rats was significantly increased（P<0.05）. The incubation period of cough was significantly prolonged（P<0.01）and the number of cough was significantly decreased（P<0.01）. The lung function of rats could be improved in different degrees in each administration group. The infiltrated area of inflammatory cells in lung tissue was reduced to different degrees，and the alveolar cavity became wider. The exfoliation of trachea epithelial cells，inflammatory cell infiltration and vascular congestion were improved to a certain extent. In addition，IFN-γ/IL-4 levels were significantly increased in each administration group（P<0.05，P<0.01）. The levels of IL-5 and IL-13 were decreased in different degrees，the collagen area around trachea was decreased，the ratios of Wat/Pbm and Wam/Pbm were decreased，andα-SMA expression was down-regulated.

Taoren（Persicae Semen）can improve the symptoms of cough and asthma in CVA rats，and have relieving cough and asthma effects. The mechanism may be as follows.①It corrects the imbalance of Th1/Th2 and reduce the infiltration of Eos，thereby reducing airway inflammation.②It decreases IL-13 concentration and reduces Wat/Pbm and Wam/Pbm to inhibit AHR.③It down-regulatesα-SMA expression and inhibits airway smooth muscle thickening and collagen deposition to slow down airway remodeling.