A computer model of woven fabric has been developed based on the geometrical and elastica model of generalized woven fabrics. A data base has been established for the fabrics previously produced and subsequently used for the design of new fabrics based on old parameters. The data base will be the basis of knowledge base of the fabric design. It has the aim of developing weaving expert system. A CAD system of 3-dimensional woven fabric structures has been also developed using Tektronix 4208 connected with mainframe with graphic system. It enables to view the 3-D structure changes of the fabric caused by relaxing or extention by internal and/or external forces after removing from the loom. It also visualizes the response of the fabric so that one can figure out the structure changes of the woven fabric during the deformation. The whole systems developed in this studies can serve as a part of expert system for woven fabric design and manufacturing.