Female body parts, such as breasts, the abdomen, and hips, have three-dimensional shapes that are important for both the ergonomics and beauty of clothing design. The purpose of this study is the three-dimensional analysis and classification of women`s abdomens using a geometric model of a three-dimensional human body. The geometric model used in this study is a method of modeling the body surface data acquired by three-dimensional measurements. It describes the shape of the body surface by means of control points on a cylindrical bi-cubic B-spline surface normalized using reference points on the body surface. The three-dimensional body shape measurement data were derived from 556 Japanese females aged 19 to 63.After finding the control points that determine the abdominal shape by applying the measurement data of each three-dimensional human body to the developed geometric model, 99 three-dimensional coordinates of the abdominal shape control points, comprising 99×3 (x, y, z coordinates)=297 coordinates, were obtained. The method used for analysis was the principal components method based on the variance-covariance matrix. The cumulative contribution rate from the first principal component to the fourth principal component was 82%, indicating that abdominal shapes can be described accurately by these four components. The 1st component describes the abdominal protrusion and waist thickness. The 2nd component describes the longitudinal length and crosswise radius of the abdomen. The 3rd component indicates the degree of slimming and skin fold droop. The 4th component describes the lower abdomen droop level and the upper abdomen swelling level.