Abstract: Four weft elastic fabrics made of a new kind of polyester (fiber——PTT) were woven.Two fabrics made of the core-spun yarn with lycra were chosen to compare with PTT fabrics. Their stress-strain curves and repeated stretch property were measured. The following things are found out:compared with the fabrics made of lycra core-spun yarn, the modulus of PTT fabrics at high strain is lower,the elongation recovery ratio of PTT fabrics is higher than the former, PTT fabrics perform a better effect of tight fitting and bonny on body than the former.