Abstract: In order to build the quantitative relationship between elastic knitted fabric and garment pattern, at first, the elastic performance tests of knitted fabric are carried out on. Then the draping operation is done for the selected knitted fabrics, and the knitted patterns considering fabric flexibility are obtained. The woven bodywear patterns are made as the standard ones. The distortion rules of all the measurements on the knitted patterns are studied by comparing the knitted patterns with the woven ones. The mathematical models of all the transverse measurements on the knitted patterns are built by using SPSS. The rationality of mathematical models is analyzed by comparing the theoretical measurements and the actual ones of the samples，and finally a mathematical model is developed for the changing rules of detailed measurement of bodywear of different elastic fabrics. This model improves the efficiency of pattern design.