Chelating networks based on modified chemically acrylonitrile with hydrazine at alkaline solution were synthesized. The resin beads with different porosities were obtained by aqueous suspension copolymerization of acrylonitrile (AN) and divinylbenzene (DVB). The unmodified and modified resins were characterized by bulk density, surface area, average pore diameter, elemental analysis (CHN), FTIR, C-13 CP/MAS NMR and scanning electronic microscopy. Elemental analyses were used to observe the increasing of nitrogen and oxygen contents due to chemical modification. Spectroscopic techniques (FTIR and C-13 CP/MAS NMR) were employed to study the structural changes provoked by the modification with hydrazine. The contents of carboxyl and amidrazone group into the copolymer structure were dependent on the reaction conditions.