Background: Comorbidities can occur frequently in patients with airflow obstruction and influence mortality and morbidity independently, deserve specific treatment. So it is increasingly recognized that many patients with chronic obstructive lung disease (COPD) have comorbidities that have a major impact on quality of life and survival. Methods: We used data obtained in the six years (2007-2012) of the Fourth and Fifth Korean National Health and Nutrition Examination Survey (KNHANES IV-V). Among 50,405 subjects, 16,151 subjects aged over 40 years who performed spirometry adequately were included in this study. Airway obstruction was defined as FEV1/FVC<0.7, and GOLD stage was used to evaluate the severity of airway obstruction. The statistical analyses were carried out using SAS 9.2 (SAS Institute Inc.). Results: Of all 16,151 subjects (43.2% male; 56.8% female), the mean age was 57.1 for men and 57.2 for women. Among them, 13.1% had obstructive lung function, 11.3% had restrictive lung function, and 75.6% was normal lung function. Among individuals with obstructive lung function, 45.3% were mild, 49.4% were moderate, and 5.3% were severe and very severe degree of airflow limitation.Prevalence of hypertension, diabetes mellitus(DM), hyperlipidemia and hypertriglycemia are higher in obstructive lung function group (35.2%vs.49.6%; 35.2%vs.49.6%; 13.8%vs.14.1%; 17.0%vs.19.7%). Hypertension is more common in subject with airflow limitation, but DM, hyperlipidemia and hypertriglycemia are less common in subject with severe airway obstruction. The prevalence of hypercholesterolemia and obesity are lower in obstructive lung function group, especially in severe and very severe groups. Conclusions: Overall, it is similar to the researchers which were conducted earlier. It showed prevalence of hypertension is common comorbid disease in COPD patients. Also, DM, hyperlipidemia and Hypertryglycemia are more common in subject with airway obstruction, but they are decreased in severe groups.