Introduction: Although H. pylori infection has been associated with many extra-gastric diseases, its effects on the decline of lung function and development of COPD is controversial. We investigated the relationship between H. pylori infection and lung function in health screening population. Methods: A retrospective cohort study was conducted using the Gene-Environment of Interaction and phenotype (GENIE) data had collected from 2004 to 2015 in Seoul National University Gangnam Health Center. The seropositivity for H. pylori and combined clinical information was assessed. The differences in development of COPD and an annual decline rate of FEV1 or FVC reduction were compared according to the positivity of H. pylori-specific IgG adjusting with age, sex, height and smoking (pack-year). Results: A total of 3619 subjects (1849 (51.1%) patients with H. pylori-specific IgG and 1770 (48.9%) patients without seropositivity) were included and their median follow-up period was 7 years. At the first year, 95 (2.6%) patients were diagnosed with COPD, but their seropositivity for H. pylori-specific IgG was not different (p=0.756). During the total follow-up periods, the incidence of COPD was not different according to seropositivity of H. pylori (2.2% in seronegative patients vs. 2.0% in seropositive patients, p=0.728). The decline rate of mean FVC was similar in both groups (35.38 ml/year in seronegative group vs. 34.34 ml/year in seropositive group; p=0.389). Also the decline rate of mean FEV₁ was not different between two groups (39.23 ml/year in seronegative group vs. 37.49 ml/year in seropositive group, p=0.086). The eradication treatment for H. pylori did not affect the rate of decline in the mean FEV1 and FVC in seropositive patients. Conclusions: No significant association was found between H. pylori infection and lung function decline rate and the development of COPD. Also, H. pylori eradication therapy did not affect the rate of lung function decline.