Purpose : Although the breast milk is the very important physiological function to women, there is no previous study on the breast milk volume of women according to Sasang Constitution. this study was to analyze the difference of breast milk volume pattern according to Sasang Constitution. Methods : This study investigated 109 breast feeding women who were treated by Spostpartum care center from March 2005 to November 2005. The result of survey was collected from the questionnaires that included postpartum pattern and QSCC H .Results : The results of Sasang Constitution analysis showed that 53 women in childbirth of 109 were classified into Soeumin(48.6%), 27 as Taeumin(24.8% ) and 29 as Soyangin(26.6% ). Mean milk volume according to the Sasang Constitution showed statistically no difference between Soeumin and Taeumin, but mean milk volume according to the Sasang Constitution showed statistically the significant difference between Soyangin and Soeumin, Soyangin and Taeumin. Conclusion These results suggest that milk volume of Soyangin is much larger than that of Soeumin and Taeumin.