Hole diameter of spinning nozzle is one of the most effective factors to control melt polymer structure development in melt spinning process. in this study, to investigate the effect of nozzle hole diameter on fiber structural development in high-speed melt spinning of high-molecular weight poly(ethylene terephthalate) (HMW-PET) of I.V. 1.21dl/g, various spinning nozzles of hole diameter 0.4, 0.5, and 0.7mm considering shear rate in the hole and draft in the spinning line were prepared. High-speed melt spinning of HMW-PET was conduct by using the prepared nozzles between 0.5 and 6km/min, and spinning temperature and throughput rate were control at 290�Ž and 4g/min.hole, respectively. Structure and properties of obtained as-spun fibers were analyzed by measurements of differential scanning calorimeter(DSC), birefringence, wide-angle x-ray diffraction(WAXD) and tensile test, and analyzed data suggested optimum shear rate and draft conditions to control melt polymer structure of HMW-PET in high-speed melt spinning.