We report on the preparation and the characterization of TiO 2 nanoparticles incorporated with nylon-6 composite nanofibers by using electrospinning technique. Two different composite nanofiber mats with TiO 2 nanoparticles sizes of 20 and 300 nm were prepared. The resultant nanofibers exhibited good incorporation of TiO 2 nanoparticles. The doping of TiO 2 nanoparticles into the nylon-6 nanofibers was confirmed by using scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD) and energy dispersive X-ray (EDX) spectroscopy. The measurement of the electrical conductivity of the TiO 2 nanoparticles incorporated with nylon-6 nanofibers were carried out. Current-voltage (I-V) characteristics revealed that the current was enhanced for the sample with 300 nm TiO 2 nanoparticles compared to that with 20-nm TiO 2 nanoparticles. © 2012 The Korean Physical Society.