A single nanostructured porous tin oxide ribbon, with its length, width and thickness of more than 1 mm, around 20 mu m and around 20 nm, respectively, were fabricated using electrospinning, and electrically characterized in a temperature range between 300 K and 90 K, a magnetic field range from -9 to 9 T (negative sign stands for the reverse direction), and the environment of air and vacuum. The electrical conductivity (sigma) of the ribbon was found insensitive to magnetic field, but sensitive to temperature and environment. Its response time to air evacuation is 67 +/- 7 s. The strong temperature dependence of sigma in vacuum is controlled by the three-dimension variable-range hopping of localized electrons.