Fe3O4 submicrospheres were synthesized by the solvothermal synthesis at 200℃, using FeCl3?6H2O and ethylene glycol as reactants. The size of as-prepared Fe3O4 submicrospheres could be controlled in the range of 115-435nm in diameter by adjusting some growth parameters. The structure, size, morphology and composition of the as-prepared Fe3O4 submicrospheres were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM). The results showed that the Fe3O4 submicrospheres were of inverse spinel structure. Magnetic propertie of 330 nm Fe3O4 submicrospheres has been detected by a vibrating sample magnetometer at room temperature. The coercive force, saturation magnetization and remanent magnetization of 330nm Fe3O4 submicrospheres are about 83.5 Oe, 81.2 emu/g and 14.6 emu/g, respectively. The influence of ethylene glycol, concentration of NaOH, and reaction time on the morphology development was experimentally investigated. It was found that ethylene glycol molecules have a significant effect on the formation of Fe3O4 submicrospheres. A possible mechanism was also proposed to account for the growth of these Fe3O4 submicrospheres.