Magnetite nanorods were fabricated by hydrothermal reduction of beta-FeOOH nanorods at 160 degrees C for 20 h. X-ray diffraction (XRD), inductively coupled plasma atomic emission spectroscopy (ICP-AES), and TEM were used to characterize structures and morphologies of the samples. On the basis of these methods, the growth mechanism was discussed. Also, the magnetic properties of the samples were characterized on a vibrating sample magnetometer (VSM).