CdS/PAN (polyacrylonitrile) composite nanowires were prepared by templated synthesis under ambient conditions, using a 4:1 (v/v) distilled water-isopropyl alcohol solvent mixture and Na2S2O3 as sulfur source. Transmission electron microscopy images showed typical CdS/PAN nanowires with diameters less than 6 nm and lengths from 200 nm to 1 mu m. CdS/PAN nanowires were also characterized by FT-infrared spectra (FTIR), X-ray powder diffraction (XRD) patterns, and UV-vis spectra. It is found that the feed mole ratio of CdCl2 to AN exerts a significant influence on the formation and morphology of CdS/PAN nanowires. In addition, possible mechanism of the reactive process was presented.