Objective:To investigate effects of external-dryness on the tissue of air-way

tracheal ciliary movement （CM） and mucoitin secretion of the respiratory tract in mice.Methods:Seventy-two Kunming mice of specific-pathogen free （SPF） were randomly divided into 4 groups

including normal temperature-damp group

normal temperature-dryness group

warm-dryness group and cool-dryness group

18 mice in each group.Histopathology

CM and mucoitin secretion were detected on the 7th and 14th days.Results:The patchy hyperplasia and loss of cilia on tracheal epithelium

alveolar congestion and edema on the 14th day were more severe than those on the 7th day with hyperplasia of about 40% of the serous gland;Pathological changes of the air-way in cool-dry group were milder with hyperplasia of about 20% of the serous gland.Compared with the normal temperature-damp group

CM was speeded on the 7th and the 14th days

and mucoitin secretion was increased on the 7th day and decreased on the 14th day in warm-dryness group （P<0.01）.In cool-dryness group

mucoitin secretion decreased on the 7th day and increased on the 14th day with CM speeded （P<0.01）.Conclusion:Warm-dryness injures the cilia-mucosa barrier of the air-way and structures of the gland and induces decrease of lung fluid production and failure in the dispersing function of the lung

which is an important pathogenesis of dry-cough.In cool-dryness group

increase of mucoitin secretion and quickening of CM are related with injury of lung-yang by cool-dryness

coagulating as phlegm-yin.CM and mucoitin secretion may provide quantitative indexes for study on pathogenesis of external-dryness.