This study surveys the optimum processing conditions of ATY for PET braiding for automotive hoses. For this purpose, high tenacity and low shrinkable PET filaments with three types of deniers are prepared. Twenty seven ATY specimens are manufactured with variation of feed speed and overfeed on the air jet texturing machine. The physical properties of various yam according to the ATY processing conditions are measured and analysed for deciding the optimum ATY processing condition. Two kinds of ATY filaments made under the optimum air texturing conditions are processed with variation of tpm, heat setting temperature and heat setting time on the 2-for-l twister and setting chamber, respectively. The optimum twisting and heat setting conditions are decided through analysis of the yam physical properties. Finally, the braiding fabric specimens are manufactured using conventional filament and newly developed filament made under optimum twisting and heat setting conditions. The bursting strengths of these braiding specimens are compared and discussed between two types of specimens.