Electrically conductive polypyrrole (PPy)/poly(p-phenylene terephthalamide) (PPTA) composite fibers have been prepared by continuous vapor phase polymerization at a speed of 0.5 similar to 1.5 m/min. The main parameters have been examined, and the conducting fibers with the best properties of electrical conductivity 0.68 s/cm, tensile strength 2731 N/mm(2), and the elongation at break 4.8% were obtained by using FeCl3 . 6H(2)O as the oxidizing agent. The results of elemental analysis, wide-angle X-ray diffraction analysis and SEM of the composite fibers are also reported.