The selectivity of a macroreticular styrene-divinylbenzene copolymer-based methylenephosphonic acid resin (RCSP) toward 17 kinds of metal ions was evaluated in nitric acid media by means of distribution ratio measurements; the order of decreasing affinity was found to be Fe(III) similar to U(VI) similar to Mo(VI) > Bi(III) > Al(III) > Gd(III) > La(III) similar to V(V)> Pb(II) > Cd(II) > Cu(II) similar to Ca(II) similar to Ba(II) similar to Zn(II) > Mg(II) similar to Co(II) similar to NI(II). Among the tested metal ions, Fe(III), Mo(VI), and U(VI) were highly distributed into RCSP even from 6 M nitric acid as in the case of solvent extraction with organophosphorous acids and eaters. However, RCSP did not exhibit as high an affinity with these metal ions in 6 M hydrochloric acid.