Abstract: Polystyrenedivinylbenze amidoxime (SDBAO) resin was synthesized by preirradiation grafting and amidoximation reaction. Acrylonitrile was grafted onto preirradiated polystyrene-divinylbenze resin in air, and the target functional group was introduced through amidoximation reaction. The chemical structure and microstructure of the products were analyzed by using FT-IR and SEM. The results show that grafting reaction only occurs at high dose (0.6-2.4 MGy), and the grafting ratio increases with absorbed dose. Based on selected irradiation conditions (2.4 MGy), SDB-AN resin is obtained by using 1∶7 acrylonitrile monomer/water ratio and reacted at 80 ℃ for 4 h, then in neutral condition SDBAO resin with satisfied properties is synthesized by SDB-AN resin and hydroxylamine hydrochloride solution at 80 ℃ for 4 h.