The mechanical properties of poly(ethylene terephthalate) (PET) fibers obtained by $CO_2$ laser-heated and high speed drawing process were investigated in terms of their dependence on the laser power and the temperature. The PET fibers were drawn with laser radiation heating under constant draw ratio (1.7) at constant feed roller speed of 100 m/min by the change in the $CO_2$ laser power from 0 to 35 W and different temperature (room temperature, $120^{circ}C;and;140^{circ}C$). The $CO_2$-laser-heated-drawn PET fibers were characterized with X-ray diffraction (WAXD), differential scanning calorimetry (DSC), birefringence and tensile testing. The mechanical properties of the PET fibers increased with increasing laser power at high temperature, which was attributed to the improvement of molecular orientation, the development of ordered crystalline structure and the increase in the crystallinity.