Multiple factors including gastroesophageal reflux disease (GERD) were evaluated for a case-control study in Chonnam area to investigate the causative entity of COPD. Data on the multiple causative factors from hospital records and interview survey were analyzed in three groups of COPD (64 cases as case group), normal lung (83 cases as control group 1) and non-COPD lung disease (45 case as control group 2). Smoking status, history of adulthood pulmonary infection and frequent history of URI, socioeconomic status, and GERD were significant different between COPD group and control group 1. Drinking status, physical height of the subjects and GERD were significant different between COPD group and control group 2. If control group 1 was used, odds ratio of GERD and COPD was 5.68 (95% confidence interval, 95% CI: 2.59-12.45) and 4.81 (95% CI: 1.89-10.53) when adjusted by age and smoking status. If control group 2 was used, odds ratio of GERD and COPD was 4.22 (95% CI: 1.69-10.56) and 4.59 (95% CI: 1.64-12.86) when adjusted by alcohol and adulthood respiratory infection status. In summary, there result suggested that GERD might play a causative role in the development of COPD.