Objective：To explore the role of neutrophil elastase（NE） and matrix metalloproteinase 12（MMP-12） in the pathogenesis of patients with chronic obstructive pulmonary disease（COPD）. Methods：Surgically resected lung specimens from 60 patients with lung cancer were collected and divided into non COPD group（A group，30 cases） and COPD patients（B group，30 cases）. Pulmonary function indexes（FEV1%，FEV1/FVC%） were detected in all patients before operation. The expressions of NE and MMP-12 in lung tissue were detected by immunohistochemical method. Results：The protein expression of NE and MMP-12 in B group was signif－icantly higher than those in A group（P<0.05）. The expression of NE in B group was negatively correlated with FEV1%，FEV1/ FVC%（r=-0.474，-0.364；P<0.05，respectively），and the expression of MMP-12 in B group was also correlated with FEV1%，FEV1/FVC%（r=-0.409，-0.791，P<0.05，respectively）. Conclusion：The over-expression of MMP-12 and NE in lung tissue associated with lung function index. MMP-12 and NE may be involved in the airway inflammation，and play important role in the airway obstruction of COPD.