Polyacrylonitrile-based carbon fibers, embedded with single-walled carbon nanotubes have been prepared by the electrospinning technique. The as-spun nanofibers were hot-stretched in an oven to enhance the orientation and crystallinity which has been confirmed by X-ray diffraction and DSC etc. With the hot-stretched process and the introduction of SWNTs, the mechanical properties of PAN nanofibers such as the modulus and tensile strength will be enhanced correspondingly. In addition, the electrical conductivities of the PAN/SWNTs nanofiber composites were also enhanced. It was concluded that the hot-stretched nanofibers and the PAN/SWNTs nanofiber composites can be used as a potential precursor to produce high-performance carbon nanocomposites. (C) 2009 Elsevier Ltd. All rights reserved.