The present study was conducted to investigate the yields of volume, thiamin and riboflavin from the milk of twenty-five Cesarean-section women, and their ingestion in infants. We measured the consumed volume of human milk of infants by the test-weighing method, and thiamin riboflavin contents were determined by fluorescence spectroscopy during the first 7 days postpartum. Thiamin contents of the milk averaged 24.3, 24.0, 27.4 and 30.2ug/100g. Thiamin and riboflavin contents of the milk both increased during the lactation ps mod(p<0.05). The first secretion of breast milk occurred from the 4th to 5th day postpartum in Cesarean-section women. The consumed volume of human milk was 63, 81, 104 and 133g/day at 4, 5, 6 and 7 days postpartum and the consumed volume of formula milk was 58, 176, 292, 323, 308, 321 and 318g/day at 1, 2, 3, 4, 5, 6 and 7 days postpartum and the consumed volume of formula from the human and formula milk were 26.6, 91.0, 151.0, 172.5, 169.2, 175.9 and 172.9ug/day. Total daily riboflavin ingestion from the human and formula milk were 26.6, 91.0, 151.0, 172.5, 169.2, 175.9 and 172.9ug/day. Total daily riboflavin ingestion from the human and formula milk was 48.7, 166.8, 277.6, 318.2, 312.0, 327.0 and 335.7ug/day at 1, 2, 3, 4, 5, 6 and 7 postpartum. These results suggest that the milk secretion of Cesarean-section women is delayed a few days and the yield volume of milk is less than that of normal delivery women, but thiamin and riboflavin contents of the milk are not different from those of milk of normal-delivery women.