Nickel/Fe3O4 nanoparticle (Ni/Fe3O4-NPs) composite coatings on the surface of carbon fiber were prepared by electrodeposition in a nickel-plating bath containing Fe3O4 nanoparticles (Fe3O4-NPs). The composite of carbon fiber with nanocomposite coatings were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) analysis, thermogravimetric (TG) analysis and vibrating sample magnetometer (VSM). The microstructure observation reveals that the Fe3O4-NPs distribute uniformly in the coatings. TG and VSM analysis show that the carbon fibers with Ni/Fe3O4-NPs composite coatings exhibit higher thermal stability and saturation magnetization than carbon fiber with Ni coatings. The result is attributed to the homogeneous distribution of magnetic Fe3O4 in the composite coatings. (C) 2011 Elsevier B. V. All rights reserved.