The complex nanorods of Fe3O4 have been selectively synthesized by an induced magnetic-field-assisted solvothermal process. X-ray diffraction (XRD), Mossbauer spectroscopy (MS), X-ray photoelectron spectra (XPS) and scanning electron microscopy (SEM) have been used to investigate the complex nanorods. Each complex of the Fe3O4 is composed of two to five nanorods. The solvothermal process under induced magnetic field makes possible to assemble the Fe3O4 nanorods. In addition, magnetic properties of Fe3O4 nanorods have been detected by a vibrating sample magnetometer, showing relatively high saturation magnetization (M-s) of -82.6 emu g(-1). The mechanism for the improved magnetic properties of the magnetite nanorods is discussed based on the oriented growth of nanoparticles. (C) 2007 Elsevier B.V. All rights reserved.