Abstract: On the basis of three-dimensional body measurements,this paper has sorted basic breast shapes of 254 women undergraduates aging from 18 to 25 in the west of China into 9 types according to the two mostly important factors embodying the beauty,i.e.,the nipple breadth and breast point.And it analysed their characteristics and chioce of bra size.It has comed to the conclusion that the proportion between the breast and torso is around 0.71 and,that between the nipple breadth and breast point,around 0.5 for young women;with respect to the choice of bra,most young women only need commom ones,then they need bras which can help heighten breasts or furl them from sides,and a few women need dubleeffect ones.The purpose of this study is to help undergarment factories set down schemes of bra manufacture and women choose fit bra.