New IPN hydrogels composed of diallyldimethylammonium chloride (DADMAC) and natural macromolecule,kappa-carrageenan (KC) were prepared by gamma irradiation and their properties were studied. The results show that boththe gel strength and the swelling capacity of the IPN hydrogels were enhanced significantly as compared with those of thepure hydrogels of PDADMAC. New IPN hydrogels composed of diallyldimethylammonium chloride (DADMAC) and natural macromolecule, kappa-carrageenan (KC) were prepared by gamma irradiation and their properties were studied. The results show that both the gel strength and the swelling capacity of the IPN hydrogels were enhanced significantly as compared with those of the hydrogel of PDADMAC.