H. pylori infection is now widely recognized as one of the causes of peptic ulcer, antral gastritis, and gastric cancer. Many data from cross-sectional seroprevalence studies have confirmed that H. pylori seropositivity varies between different area and race of the same country. The aim of this study is to evaluate the H. pylori seropositivity in 3,488 healthy subjects who reside in Metro-Inchon. Methods : H. pylori IgG antibodies were assayed by enzyme linked immunosorbent assay(ELISA) in healthy Koreans who underwent health examination in Gil Hospital from January to September, 1997. Subjects who had past history of peptic ulcer and previous gastric or duodenal operation and used antibiotics in 1 month were excluded. We compared H. pylori seropositivity between sex, age group, and ABO blood group using Chi-square test and Mantel-Haenszel Chi-square test. Results : 1) The overall seropositivity of H. pylori infection was 70.0%. 2) The seropositivity of H. pylori infection by age groups was 28.6% in 10-19, 63.3% in 20-29, 65.5% in 30-39, 70.7% in 40-49, 73.3% in 50-59, and 74.8% in over 60. 3) The seropositivity of H. pylori infection was 72.1% in male and 65.8% in female. 4) The seropositivity of H. pylori infection among ABO blood groups were 69.4% in A, 69.8% in B, 70.7% in O, and 70.1% in AB. Conclusion : The seropositivity of H. pylori infection in healthy persons living in Metro-Inchon was 70.0% and increased with age and was higher in male.