Polyacrylonitrile (PAN)/Fe3O4 composite nanofibers were prepared via the electrospinning of the PAN spinning solutions with magnetite Fe3O4 nanoparticles. The experimental results showed that the morphology and diameter of the nanofibers strongly depended upon concentrations of PAN and salt additives in the spinning solutions. A suitable PAN concentration and LiCl additives could effectively prevent the occurrence of beads in the electrospinning process and affected the diameters of the electrospun nanofibers. The breaking strength and breaking strain decreased when the magnetite Fe3O4 nanoparticles were incorporated. The prepared PAN/Fe3O4 nanofibers were superparamagnetic at room temperature. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 115: 1781-1786, 2010