A novel approach, combining in-situ composite method with electrospinning, was used to prepare high magnetic Fe3O4/poly(vinyl alcohol) (PVA) composite nanofibers. Fe3O4 magnetic fluids were synthesized by chemical co-precipitation method in the presence of 6 wt.% PVA aqueous solution. PVA was used as stabilizer and polymeric matrix. The resulting Fe3O4/PVA composite nanofibers were characterized with field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and X-ray diffractometer (XRD), respectively. These composite fibers showed a uniform and continuous morphology, with the Fe3O4 nanoparticles embedded in the fibers. Magnetization test confirmed that the composite fiber showed a high saturated magnetization (M-s = 2.42 em mu.g(-1)) although only 4 wt.% content. (C) 2009 Elsevier B.V. All rights reserved.