Abstract: Polyaniline nanotube have been successfully synthesized by chemical oxidizing process at -20 ℃. As demonstrated by SEM, TEM, IR, and applying the 4 probes method diameters ranging from 20 nm to 30 nm and high conductivity about 138 S/cm are attained, appearing to be much higher than that are obtainable with other processes. The effects of reaction time, concentration of HCl solution and mole ratio of ammonium persulfate to aniline on the conductivity of polyaniline nanotubes are discussed.