A hydrogel copolymer of N-isopropylacrylamide/β-cyclodextrin was prepared by radiation copolymerization method. β-cyclodextrin (β-CD) based monomer (MAH-β-CD) containing vinyl and carboxyl functional groups was synthesized by modification of β-CD with maleic anhydride (MAH). And then the mixture aqueous solution of NIPAAm and MAH-β-CD was irradiated by electron beams with BIS as cross-linking agent for sample of poly (NIPAAm-co-MAH-β-CD) hydrogel. The effects of temperature, pH and ionic strength on swelling ratio of the hydrogel were determined meanwhile the effect of irradiation absorbed doses on its swelling and deswelling properties was also described. Experimental results show that the copolymer hydrogel possesses temperature, pH and ionic strength sensitive functions.