Carbonizable polymers were electrospun in the form of web for electrode preparations of electrical supercapacitors. The polymers chosen were polyacrylonitrile (PAN), PAN/muti-wall carbon nanotube (MWCNT) blends, polyimide (PI), polybenzimidazole (PBI), and isotropic pitch precursor (IPP). These were successfully electrospun with wide range of average fiber diameter 50-2000 rim. The web were stabilized and activated under steam at various temperatures resulting specific surface areas 1000-2500 m(2)/g. The electrical conductivities of the carbonized webs at 1000 degrees C were in the range of 2-80 S/cm, showing lowest value from PAN and highest value from IPP reflecting morphological structures of carbonized fibers. All the supercapacitors made from the activated carbon nanofibers (ACNFs) showed excellent capacitances of 120-210 F/g at high current density of 1000 mA/g, related to their high electrical conductivity.