The fibrous structure of V2O5 colloids has been known for a long time [33]. Electron microscopy shows that V2O5 nH2O gels are bundled of ribbon-like fibres about 10 nm wide and over 1 mm long [34]. The detailed structure of vanadium pent-oxide gels had been studied by Livage et al. [35]. There are some obvious advantages about using these contamination-free sol as a precursor to prepare VO2. Compared with bulk V2O5, the surface area is larger and the reduction process could be performed uniformly under stirring. For bulk V2O5, while the surface was tend to be reduced deeply , inner part would remained intact during pre- reduction. That would make the control of the chemical valence of vanadium difficult.