To study the relation between serum fatty acids and coronary artery disease(CAD), 194 subjects were randomly selected and divided into three groups(control, single vessel disease group(SVD), muliple vessel disease group(MVD)) according to the angiographic results. Total serum levels of fatty acids and serum phospholipid(PL)-fatty acids(FAs)were analysed using gas chromatography and their associations with CAD were examined. Different patterns of total serum fatty acid levels were found in men and women. Levels of most fatty acids of SVD and MVD were significantly lower in men, while those of MVD were significantly higher in women. In terms of PL-FAs in both men and women, the levels of PL-FAs follow the order of control < SVD < MVD and in women, the difference was significant. Various ratio(including ratios denoting the activites of desaturase and elongase) of total serum-and PL-FAs were similar in the three groups. In the relation of serum fatty acids to serum lipid profiles, PUFA & LDL showed a negative correlation, while, SFA & LDL-cholesterol and PUFA and HDL-cholesterol showed positive correlatons. correlations. Systolic blood pressure and alcohol intake levels negatively affected the levels of serum LA, AA, EPA and DHA in the risk factor analysis. These findings are consistent with other evidence indicating that fatty acid compositions are changed in CAD, especially on the concentration base and the change was related to the severity of the disease. Therefore, for the purpose of disease prevention and therapeutic use, balanced intakes of various fatty acids must be seriously considered.