The objective of this study was to determine β-casein adsorption by using supermacroporous poly(2-hydroxyethyl methacrylate-N-methacryloyl-(l)-histidine methyl ester) [p(HEMA-MAH)] cryogel. β-Casein adsorption properties of p(HEMA-MAH) cryogel were studied for the application of β-casein purification. The cryogel was produced by free radical polymerization initiated by N,N,N’,N’-tetramethylene diamine and ammonium persulfate pairs in an ice bath. P(HEMA-MAH) cryogel was characterized by swelling tests, Fourier transform infrared spectroscopy, and scanning electron microscopy. The effects of the flow rate, pH, temperature, initial β-casein concentration, and ionic strength on the adsorption efficiency of cryogel were studied. The equilibrium swelling degree of the p(HEMA-MAH) cryogel was 6.73 g H2O/g cryogel. β-Casein adsorption capacity of p(HEMA-MAH) cryogel from aqueous solution was estimated as 31.17 mg/g cryogel. It was also observed that β-casein could be repeatedly adsorbed and desorbed with p(HEMA-MAH) cryogel without significant loss in the adsorption capacity.