In order to investigate calcium , phosphorous and magnesium intake of breast-fed infants, consumed volumes of human milk and those mineral contents of the milk were examined at 0.5, 1, 2, 3, 4 and 5 months of lactation. Calcium , phosphorus and magnesium contents of human milk during the first 5 months of lactation averaged 26.0, 13.7 and 3.70mg/100g, respectively. Calcium intake of infants averaged 192.3 and 171.0mg/day which represented 39.7 and 33.5% of the RDA for boys and girls, respectively. Phosphorus intake of infants averaged 100.7 and 85.2mg/day which represented 26.2% and 23.4 % of the RDA for boys and girls respectively. The calcium /phosphorus ratio of human milk averaged 2.00 during lactation. The results of this survey suggest that, the reevaluation of calcium , phosphorus and magnesium intake and recommended dietary allowance of these nutrients during infancy is merited.