OBJECTIVE: To investigate the effect of Daiqin phlegm-expelling pill, prepared with Traditional Chinese Medicine(TCM), on the development of inflammation in Sprague-Dawley(SD) rats with chronic obstructive pulmonary disease(COPD) induced by lipopolysaccharide(LPS) and smoke, and to identity the possible underlying mechanism.METHODS: Sixty male rats were divided into 6 groups(healthy control group, untreated group,Daiqin phlegm-expelling pill low, middle and high dose, and ambroxol hydrochloride tablet group).COPD was established in SD rats by sootiness and tracheal instillation with LPS. The rats were treated with Daiqin phlegm-expelling pill at the indicated doses for 28 d, the inflammatory cells in bronchoalveolar lavage fluid(BALF), the concentration of tumor necrosis factor-α(TNF-α), interleukin(IL)-8 and IL-6 in blood and the inflammation in lung were evaluated.RESULTS: The number of inflammatory cells in the BALF and TNF-ficantly redα, IL-8 and IL-6 level in plasma were signiuced in rats with COPD when treated with Daiqin phlegm-expelling pill or ambroxol hydrochloride tablet, compared with those without any treatment. The Daiqin phlegm-expelling pill treated rats with COPD had a attenuated inflammation in lung tissue, compared with the untreated group.CONCLUSION: Daiqin phlegm-expelling pill can significantly restrain the airway inflammation in rats with LPS-smoke induced COPD.