A nanocomposite consisting of vanadium pentoxide (V,2,O,5,) and polyaniline (PAn) was prepared by ,in-situ, intercalative polymerization, and irradiation effects on structure and properties of the PAn/V,2,O,5, nanocomposite have also been investigated by using thermogravimetric analysis, FT-IR, X-ray diffraction, conductivity measurement and cyclic voltammetry. The results show that irradiation is of advantage to improvement of thermal stability and specific capacity of PAn/V,2,O,5, nanocomposite for rechargeable lithium batteries. However, irradiation has no effect on interlayer spacing of V,2,O,5, xerogel and crystalline size obviously.