To observe the effect of Qingfei Xiaoyan Pills on the expression of matrix metalloproteinase-9(MMP-9) and tissue inhibitor of metalloproteinase-1(TIMP-1) in the lung tissue of COPD Rats. Methods:Thirty Wistar rats were divided into 3 groups randomly， normal control group， COPD model group， Qingfei Xiaoyan Pills group. Except for the normal control group， we made the COPD model by smudging plus intratracheal instillation of LPS under endoscopy， and treated them separately for 7days. Then we observed the change of MMP-9 and TIMP-1 expression in the lung tissue. Results:The MMP-9and TIMP-1 expression in the lung of COPD model group were obviously increased than those of control group(P<0.05)， the MMP-9 and TIMP-1 of Qingfei Xiaoyan Pills group were lower than those of model group (P<0.05).Conclusion: Qingfei Xiaoyan Pills could inhibit the expression of MMP-9 and TIMP-1 in the lung in COPD rats， improve the MMP-9 / TIMP-1 imbalance， thus playing a role in preventing and treating airway remodeling in COPD.