Vanadium oxide nanotubes (VO_x-NTs) were obtained as the main product in a sol–gel reaction followed by hydrothermal treatment from V₂O₅ precursors and primary amines. The material has a considerable large distance between the layers (ca. 3.5nm), a wide inner (15–40nm) and outer diameter (60–100nm), and the open tube ends which are favorable for the magnesium ion insertion. VO_x-NTs are a new kind of material with a unique nanostructured morphology, which can electrochemically insert/deinsert magnesium ions reversibly from the cyclic voltammogram. AC impedance (EIS) demonstrated that Mg²⁺ diffusion into the nanotubes is faster than polycrystalline V₂O₅ during intercalation Mg²⁺ into the cathodes. X-ray photoelectron spectroscopy (XPS) and X-ray powder diffraction (XRD) results gave the mechanism of Mg²⁺ insertion into the nanotubes, however, the specific capacity of the rechargeable magnesium is lower than that of lithium.