Abstract: Objective To investigate the changes of aromatic hydrocarbon receptor and cyclooxygenase-2 levels in bronchial lavage fluid of patients with chronic obstructive pulmonary disease and its clinical significance. Methods Ninety-four COPD patients diagnosed in respiratory department of our hospital were selected as case group and 88 healthy persons as control group. The levels of aromatic hydrocarbon receptor(AHR), cyclooxygenase-2(COX-2), CD44, Th17, IL-4, IL-8, IL-10, TNF-α and hs-CRP in bronchial lavage fluid were measured. Pearson correlation analysis and logistic regression analysis were used to explore the diagnostic and prognostic significance of AHR and COX-2 in COPD patients. Results The levels of AHR and IFN-γ in bronchial lavage fluid of the case group were lower than those of the control group, and the levels of COX-2, CD44, IL-4, IL-8, IL-10, TNF-α, hs-CRP and TH17 were higher than those of the control group(all P<0.05). The negative correlation between AHR and CD44, IL-4, IL-8, IL-10, TNF-α, hs-CRP, TH17 were significant, and the positive correlation between COX-2 and CD44, IL-4, IL-8, IL-10 were significant(all P<0.05). The TNF-α, hs-CRP and TH17 were positively correlated with IFN-γ(all P<0.05). High levels of COX-2, TH17 and low level of AHR were risk factors for death in patients with COPD(P<0.05). The AUC of COX-2 and AHR were similar, both were less than that of AHR + COX-2. The sensitivity and specificity of COX-2 and AHR in diagnosis of COPD were similar(P>0.05). They were all less than that of AHR + COX-2(P<0.05). Conclusion The level of AHR in bronchial lavage fluid of COPD patients decreased, and the level of COX-2 increased. The imbalance of a series of inflammatory factors may be the pathogenesis of COPD. AHR + COX-2 has high sensitivity and specificity in the diagnosis of COPD, and is worthy of clinical application.