Background and objective: Growing body of evidence suggests that circulating adiponectin may play a significant role in the development of the metabolic syndrome (MetS). Little is known regarding the significance of circulating adiponectin as a surrogate marker for MetS in a large cohort population. Therefore, we sought to evaluate in a large-scale population cohort the potential interrelationships between circulating adiponectin concentration and the component of MetS. Methods: The study enrolled 3,508 subjects [1,437 men (mean age; 56.9 짹 7.9) and 2,071 women (mean age; 55.8 짹 8.1)] from the Korean Rural Genomic Cohort (KRGC), an ongoing epidemiologic study conducted on a senior (aged > 45years) population. We defined the MetS by Asian modified criteria of the National Cholesterol Education Program���s Adult Treatment Panel III report. The serum concentrations of adiponectin were measured by a radioimmunoassay (RIA) system (LINCO Research, Inc. USA). Results: The mean adiponectin levels for components with 0, 1, 2, 3, 4, or 5 characteristics of the MetS in men were 11.19, 10.08, 8.09, 7.14, 6.21, and 5.11 µg/L, respectively (p <0.0001) and those in women were 15.65, 14.03, 12.38, 11.04, 9.75, and 9.32 µg/L, respectively (p <0.0001). Adiponectin concentrations correlated negatively with waist circumference & HOMA-IR and correlated positively with high-density lipoprotein in both sexes (p <0.001). Multiple logistic analyses demonstrated that circulation adiponectin exhibited a strong protective effect of the presence of metabolic syndrome [OR; 0.324 (0.255-0.411) in male, 0.324 (0.259-0.404) in female]. Conclusions: Serum adiponectin is a strong associated phenotype of MetS as well as the component of MetS in a Korean senior rural cohort population. It suggested that serum adiponectin could become a surrogate target for reducing the morbidity and mortality associated MetS.