Hydrophilic copolymer beads, APPO-DMAAm-4G having phosphinic acid groups were prepared by suspension copolymerization of acryloyloxypropyl n-octylphosphinic acid (APPO), NN-dimethylacrylamide (DMAAm), and tetraethyleneglycol dimethacrylate (4G) dissolved in chloroform in a saturated Na2SO4 aqueous solution in the presence of surfactant and MgCO3. The adsorption abilities for metal ions of the copolymer beads were studied. The APPO-DMAAm-4G copolymer beads had higher adsorption ability for lanthanide metal ions (Eu3+, Sm3+, Nd3+ or La3+). Furthermore, it was also found that the APPO-DMAAm-4G copolymer beads had selective adsorption ability for lanthanide metal ions in the following order: EU3+ > SM3+ > Nd3+ > La3+. (c) 2005 Elsevier B.V. All rights reserved.