We assessed composition of plasma fatty acids and eicosapentaenoic acid (EPA)/arachidonic acid (AA) ratio in healthy subjects and patients with coronary artery disease (CAD) living in local urban area surrounding farm villages. We enrolled 134 apparently healthy subjects (males: 57, females: 77, 71±13 y-o) and 506 patients (CAD: 153 pt, non-CAD: 353 pt). Negative correlation was demonstrated between serum AA and age. EPA/AA ratios were significantly elevated as the age increased. Net volumes of serum fatty acid without EPA were higher in normal younger/middle than normal elder people, but percent volumes of all fatty acid showed insignificant correlation with both groups. The values of EPA/AA ratio were not significantly different among normal controls (0.46±0.23), CAD (0.48±0.28) and non-CAD (0.45±0.28). In conclusion, no relationship was identified between EPA/AA ratio and CAD in old subjects. KEY WORDS: eicosapentaenoic acid (EPA), arachidonic acid (AA), EPA/AA ratio, coronary artery disease, rural area