Novel Fe3O4/carbon nanotubes (CNTs) nanocomposites were prepared by a polyol-medium solvothermal method using oleate as an interlinker molecule and characterized via X-ray diffractometry, X-ray photoelectron spectroscopy, transmission electron microscopy and vibration sample magnetometry. Results indicated that the Fe3O4 nanoparticles were successfully attached on the surface of CNTs and the nanocomposites were proved to be superparamagnetic with saturation magnetization of 50.0 emu g(-1). A proposed formation mechanism of the magnetic nanocomposites was presented. (C) 2009 Elsevier B.V. All rights reserved.