In order to prepare the heavy metal adsorbent, PAN nano fiber web was prepared by electro spinning and subsequently amidoximated with hydroxyl amine. The diameter of fiber depended on the polymer concentration and the applied voltage. The average diameter increased with an increase of the polymer concentration and decreased with the applied voltage. Both the prepared nano fiber web and PAN fiber for weaving were amidoximated by the reaction of PAN with hydroxylamine. The formation of amidoxime groups was identified by FT-IR spectra and elemental analyses. The degree of amidoximation of PAN nano fiber was increased with increasing temperature. Amidoximated PAN nano fiber web had an excellent adsorption capacity for heavy metal ions, especially $Cu^{+2}$, compared with the amidoximated PAN fiber for weaving due to the relatively large specific surface area.