Nano-sized magnetite (Fe3O4 ) was prepared using dry and wet chemical methods in presence of surfactants as capping agents. The synthesized materials were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The X-ray diffraction pattern showed cubic spinel crystal structure for all samples. Particle size in the range of 8-55 nm was obtained. The electrical properties (electrical conductivity σ and dielectric constant ε`) of synthesized samples were measured using two-point probe electrical resistivity techniques. Effects of preparation methods and γ- irradiation process on each of the morphology and electrical properties of the prepared samples were studied and discussed. The electrical properties were explained according to electron hopping mechanism between Fe2+ and Fe3+ ions and found to be dependent on each of particle size and γ- irradiation process