ObjectiveTo explore the relationship of levels of serum interleukin-6 (IL-6), tumor necrosis factor-α(TNF-α) and C-reactive protein (CRP) with lung function in elderly patients with stable COPD and whose pulmonary function classification was levelⅡor above. MethodsSixty elderly patients with stable COPD and with the pulmonary function classification of levelⅡor above and 35 age-matched healthy subjects in the Gansu Provincial Hospital from November 2012 to March in 2014 were recruited in the study.Serum IL-6, TNF-αand CRP levels were detected by electro-chemiluminescence immunoassay (ECLI), enzyme-linked immunosorbent assay and immunoturbidimetric assay, respectively.And their relationships with lung function were explored by Spearman correlation analysis. ResultsThe levels of serum IL-6[(33.0±15.1) mg/L vs.(15.9±8.7) mg/L], TNF-α[(53.8±20.1) pg/mL vs.(22.2±8.0) pg/mL] and CRP[(8.7±3.9) mg/L vs.(5.8±2.3) mg/L] were significantly higher in the stable COPD patients than those in the healthy controls (P < 0.01).With the increase of COPD severity grade, the levels of serum IL-6, TNF-αand CRP increased gradually, and the lung function of FEV1%pred and FEV1/FVC decreased gradually (P < 0.05).The levels of serum IL-6, TNF-αand CRP were negatively correlated with lung function (P < 0.05). ConclusionsThere is airway inflammation in elderly patients with stable COPD.Airway inflammation may be the reason of the decline of pulmonary function in patients with stable COPD.