A comprehensive apparel CAD system performing automatic two dimensional garment pattern drafting, optimum allocation of patterns on the cloth, and the prediction of the final drape shape of designed garment putting on the human body was developed. The two dimensional garment pattern drafting is based on the concept of creating basic pieces from the formulated design script. For the accuracy as well as convenience of designing purpose, apparel CAD specific functions such as dart manipulation have been generated. Optimum pattern allocation algorithm has been developed based on the idea of minimizing the evaluation function which has the positions of the patterns as dependent variables, using the conventional pattern boundary checking algorithm during the allocation process instead of dividing patterns into fine grids. To predict the draped garment shape, we first divided designed garment pieces into fine quadrilateral elements using a specially designed mesh generator and assigned a sewing condition to make a three dimensional shape. Final shape is predicted in relatively short time considering the contact condition with human body, deformation, the weight of the garment pieces, and the surface texture of the cloth.