This research surveys the relationship between mechanical properties of polyester filaments and fabrics treated with various wet and dry heat temperatures in dyeing and finishing processes including sizing. Used polyester filament for warp is 50d/24fil spark, and 75d/72fil semi-dull for weft. Plain fabrics were woven by shuttle weaving machine. Heat temperatures treated in sizing process are 90'C, 125'C and 150'C with dry heat, 90'C, 110'C and 120'C with wet heat in scouring and relaxation process, 180'C, 200'C and 220'C with dry heat in pre-set process, and 170'C, 180'C and 200'C with dry heat in final set process. Modulus, tenacity and strain of the filaments taken from fabrics of each specimen are measured with Instron. Mechanical properties of fabrics treated with various wet and dry heat temperatures such as tensile, bending, shear and compression were also measured. Theses mechanical data of yarns and fabrics are analyzed with various dry and wet heat temperatures, and with variation according to each process.