The present study was carried out in normal and atherosclerotic New Zealand white(NZW) rabbits, to evaluate the effect of dietary supplementation with Korean pinenut oil, on the total fatty acid composition of red blood cell membranes. Erythrocyte fatty acids of chain lengths ranging fro 12 : 0 to 22 : 6$omega$3 were identified. In study I, palmitic acid(16 : 0) was found to be the main erythrocyte membranes fatty acid, followed in turn by stearic(18 : 0), oleic(18 : 1), and linoleic acids(18 : 2$omega$6). There was a large increase in the proportion of 20 : 4$omega$6 in 10% pinenut oil group on days 40 and 80(compared with control), although the increase was not statistically significant. Most erythrocyte fatty acids were less affected by the types or levels of oils supplemented for periods fo 40 and 80days. In study II,at the end of the dietary treatment, the levels of 12 : 0, 14 : 0, 15 : 0 and 18 : 0 were significantly decreased in the 5% soybean oil/cholesterol group, whereas those of 12 : 0, 14 : 0 and 18 : 0 were significantly decreased, but that of 18 : 2$omega$6 was significantly increased in the 10% soybean oil/cholesterol group, compared to the cholesterol group. No significant differences in fatty acid composition were seen between the pinenut oil/cholesterol group, whereas the 10% soybean oil/cholesterol group had significantly elevated 18 : 2$omega$6, compared to the cholesterol group. The proportion of 18 : 4$omega$6 was significantly raised in the 5% soybean oil/cholesterol and 5% pinenut oil/cholesterol group, and the content of 16 : 1$omega$7 was significantly lowered in the 5% and 10% soybean/cholesterol groups, compared to the cholesterol group at 10 weeks supplementation. In studies I,II and III, the total proportions of saturated fatty acids were not significantly affected by the types of levels of oils supplemented throughout the study period.