The intercalation compound Li1+xV3O8 has been prepared successfully and investigated by X-ray powder diffraction and quantitative element analysis. The compound was also studied with 7Li NMR (on line width) in temperature range 298-400K by using SXP4-100 NMR spectrometer at a frequency f = 35.03 MHz. The active energy of Li+ion, Ea = 0.18eV, is derived from the line width of the motional narrowing. The conductivity is 10-3Ω-1·cm-1 at room temperature.