Large-scale single crystalline vanadium oxide nanobelts were synthesized by hydrothermal treatment of NH4VO3 in the presence of polymer PEG-4000 at 180 °C for 24 h. Techniques of SEM, TEM, XRD, FT-IR, HRTEM, and SAED were used to characterize the morphology, composition and structure of the as-obtained nanobelts. The as-prepared vanadium oxide nanobelts are up to several hundreds micrometers in length, 100 nm-1 μm in width, 20-30 nm in thickness, and grow along the [1 0 0] direction. PEG plays a critical role for the formation of the vanadium oxide nanobelts in the present synthetic sys...