This study was aimed at evaluating the nutritional status of Korean lactating women, who were attending peripheral community clinics in low-income areas, by anthropometric measurement, estimating dietary intakes and analyzing the contents of breast milk components, serum lipid content and fatty acid composition. Regarding anghropometric measurements, maternal circumferences decreased significantly at the trunk but not at the limbs. The skinfold thickness on all regions had the tendency to decrease during lactation. It was found that intakes of energy, protein, lipid and carbohydrates were desirable while calcium, zinc, copper and vitamin A were low and sodium was excessive. The energy $\%$of fat was 22.41$\%$of the total energy which is higher than the RDA for adults but it is proper for lactating women, but energy $\%$ from each fatty acid was usually low and an intake ratio of $omega$6/$omega$3 fatty acids was desirable. Accordingly, it is thought that dietary fat intake was balanced in quality. Concentrations of the nutrients in matured human milk showed the same range as that reported form different regions with the exception of calcium and magnesium which were relatively low. Serum lipid contents were decreased with the time postpartum and the average serum lipid content of lactating women were similar to the normal range of adults. Serum polyunsaturated fatty acids. especially $omega$6 fatty acids have gradually increased with the time postpartum, but the composition were not greatly influenced by dietary intakes.