Objective:The purpose of this experiment is to investigate the impact of tiotropium on the pathological process of chronic obstructive pulmonary disease（COPD） and respiratory function.Method: Wistar rats were randomized into three groups:normal control group（group A）

COPD group（group B）

tiotropium bromide treated group（group C）.The COPD rat model was constructed by intratracheal instillation of 200 μg lipopolysaccharide three times and daily exposure to cigarette smoking

in 12 weeks.Histological examination on the right side of the mid-lung tissue was performed with Hematoxylin-Eosin staining.The concentrations of IL-6 and LTC4

total and differential cells counts in bronchoalveolar lavage fluid（BALF）were examined

and the concentrations of IL-6 and LTC4 in blood surem were also examined by ELISA.Result: Severe lung inflammation and decreased lung function were demonstrated in the group B compared with those in the group A.The inflammatory cell counts in BALF

and the levels of IL-6 and LTC4 in BALF and serum were significantly increased in the group B compared with those in the group A.Tiotropium bromide administration improved the parameters above.①The body weight decreased significantly after four weeks in the group B compared with the group A（P<0.05）;Compared with the group B

thiophene care bromide interventional treatment after two weeks the body weight was gained（P<0.05）.② Respiratory function was significantly deteriorated in the group B compared with those in the group A.Tiotropium repair improved compared with the group B.③ lung inflammation and emphysema were demonstrated in the group B compared with those in the group A.The group C also appeared inflammation and emphysema

but to a lesser extent.④ The inflammatory cell counts in BALF

and the levels of IL-6 and LTC4 in BALF and serum were significantly increased in the group B compared with those in the group A（P<0.05）.Tiotropium bromide administration improved the above parameters（P<0.01）.Conclusion: Tiotropium bromide administration can significantly reduce the inflammatory cells infiltrating the lung

and the levels of IL-6 and LTC4 in BALF and serum in the COPD rats.The pathological conditions and respiratory function in the COPD rats can be improved.