Objective To investigate the relationship between inflammatory indexes, immunoglobulins and pulmonary function, severity of pulmonary ventilation dysfunction in patients with chronic obstructive pulmonary disease (COPD). Methods 107 patients with COPD in the hospital from January 2020 to June 2024 were classified into mild-to-moderate group (n=58) and moderately severe, severe and extremely severe group (n=49) by means of the severity grading of pulmonary ventilation dysfunction. Another 102 health examination subjects during the same period were selected as the control group. Inflammatory indexes ［C-reactive protein (CRP), procalcitonin (PCT), interleukin-6 (IL-6)］, immunoglobulins (IgM, IgA, IgG) and lung function indexes (FEV1, FVC, FEV1/FVC) were measured among all study subjects after admission. Pearson correlation analysis was applied to analyze the correlation between CRP, PCT, IL-6, IgM, IgA, IgG and FEV1, FVC, FEV1/FVC. Spearman correlation analysis was adopted to analyze the relationship between CRP, PCT, IL-6, IgM, IgA, IgG and severity grading of pulmonary ventilation dysfunction. Results The CRP, PCT and IL-6 levels in the study group were higher while the IgA, IgG, FEV1, FVC and FEV1/FVC were lower (P<0.05). Pearson correlation analysis indicated that the levels of CRP, PCT and IL-6 were inversely related to FEV1, FVC and FEV1/FVC (r=-0.482,-0.476, -0.374; -0.468, -0.453, -〗0.363; -0.376,-0.364, -0.345, P<0.05), and IgA and IgG were positively correlated with FEV1, FVC and FEV1/FVC (r=0.403, 0.412, 0.373; 0.345, 0.327, 0.308, P<0.05). The levels of CRP, PCT and IL-6 in severe and extremely severe groups were higher than those in mild and moderate groups, In the moderate group, IgA and IgG were lower than those in the mild and moderate groups (P<0.05).There was no obvious difference in IgM among patients with different grades of pulmonary ventilation dysfunction severity (P>0.05). With regard to Spearman correlation analysis, the CRP, PCT and IL-6 were positively associated with severity grading of pulmonary ventilation dysfunction (r=0.518, 0.513, 0.496, P<0.05). IgA and IgG were inversely proportional to pulmonary ventilation dysfunction severity grading (r=-0.293, -0.285, P<0.05).Conclusion Inflammatory indexes and immunoglobulins in COPD patients are closely related to lung function and severity grading of pulmonary ventilation dysfunction. Clinically, early determination of inflammatory indexes and immunoglobulins can provide certain reference value for the evaluation of lung function and severity of COPD patients