The mechanical properties of fabric have an influence on clothing performance such as fabric handle which depends on the processing shrinkage. This paper surveys correlation between the mechanical properties and the processing shrinkage of polyester plain woven fabric with variance of fabric structural parameters. The main structural parameter is warp density including various weft densities, and linear densities of weft yarns. Mechanical properties of polyester fabric were measured by KES-FB system. The effects of fabric warp density on the processing shrinkage, and the mechanical properties of fabrics are analyzed.