The longitudinal changes on human milk volume per day and lactational performance of Korean primiparae(n=9) and multiparae(n=6) from 0.5 month to 5 months after parturition have been studied by test-weighing method. The human milk volume per day tended to increase during lactation. The mean volume to the 3rd month of lactation was 643m1 for primiparae and 654m1 for multiparae, and it was 647 $pm$ 182m1 for both of them. The mean volume to the 5th month of lactation was 648m1 for primiparae and 668m1 for multiparae, and it was 658$pm$186$mell$ for both of them. The peak volume was observed at the 1st month of lactation in 8 women of 15 lactating women, that is, 53.3% . The high distributions of the individual mean volume to the 5th month were found 550~650$mell$(40.0% ) and 650~750$mell$(26.7% ). and 13 women of 15 lactating women(86.6% ) were observed below 750m1. The number of feeding per day was 7.7~9.3 to the 5th month and the mean volume per feeding was 65~101$mell$. While the former tended to decreased, the latter increased during lactation. The human milk volume was correlated with the peak volume. but not with maternal age. weight before delivery. maternal height and birth weight. As mentioned above, the human milk volume of Koreans was about 658$pm$ 186$mell$ and 86.6% of it was below 750$mell$. So the human milk volume, referred to as 800$mell$ in recommended dietary allowances for Koreans might be estimated over real amount. It is necessary to study according to regions. socioeconomic levels. maternal nutritional status and the early stage of lactation.