In this work, the structure, mechanical and thermal properties of PET fiber obtained by hot multi-stage drawing have been investigated in terms of their dependence on the number of drawing steps at an equivalent total draw ratio. Differential scanning calorimetry, birefringence, wide-angle x-ray diffraction, FTIR spectroscopy, tensile properties, and taut-tie molecules were used to characterize the fine structure and physical properties of the fibers. Results have been explained in terms of a higher drawing residence time at an equivalent drawing speed. For single stage drawn fiber, a high tensile strength is obtained, whereas a high initial modulus is obtained for fiber drawn at three-stage drawing. According to the results, an important finding is that three-stage drawing process has the potential to produce high-modulus fibers. The enhanced fraction of taut-tie molecules is found in three-stage drawn fiber, which is believed to be one of the important factors leading to the high modulus achieved in fibers drawn in hot multistage