The aim of this work is to develop sense-differentiated textiles using Thick-Thin polyester yarn(T-T yarn) with finer than 1 denier mono filament. The ITY(Interlace Textured Yarn) using T-T yarn with various over feed ratios of PET filament was manufactured with different shrinking percentage of core yarn and then the fabrics were woven on the same weaving 100m using ITY produced. The mechanical properties and the handles of the fabrics were examined with KES-FB system suggested by Kawabata. The shrinkage of ITY was increased with decreasing over feed ratio and increased with increasing heat treatment temperature of T-T yarn. The initial elasticity modulus of ITY was decreased with increasing over feed ratio and heat treatment temperature of T-T yarn. The tensile energy of fabrics was decreased with increasing of over feed ratio, but bending rigidity and shear rigidity of fabrics were increased with increasing of over feed ratio of PET filament. The results indicate that the fabric using T-T yarn with finer than I denier mono filament can be used for the purpose of sense-differentiated textile.