目的 Long-term inhalation of cigarette smoke or air pollutants can both result in the cough hypersensitivity. Many researchers reported that amount of reactive oxygen species were consisted in cigarette smoke and air pollutants. Present study aims to investigate the relationship between airway oxidative stress induced by H2O2 and cough sensitivity, and to establish an appropriate nebulizing concentration of H2O2 and nebulizin exposure time for the modeling. 方法 SPF grade Balb/c were randomly grouped according to nebulizating concentration(0.2％, 1％, 5％) and exposure time(3 d, 7 d, 10 d, 14 d). Another 3 n-acetylcysteine(NAC)intragastrical treatment groups would be seted up in each concentration corresponding to the model control group which present the highest frequency in cough times. Mice were exposed in H2O2 via nebulizer in a chamber. Each nebulization remains for 20min twice a day. NAC intragastrically administration were manipulated between two nebulization. A capsicin cough challenge was manipulated in the day after termination of nebulization. After cough challenge, animals were sacrificed. Bronchoalveolar Lavage Fluid (BALF) were gathered for total cell counts and differential leukocyte counts. Lung tissues were also gathered for real time PCR for Transient receptor potential vanilloid 1(TRPV1), Transient receptor potential ankyrin 1(TRPA1) mRNA expressions and detecting superoxide dismutase (SOD) activity, glutathione peroxidase (GSH-px) activity. 2 mice in each groups were selected for trachea and lung tissues histological evaluations.