Three network crown ether resins with a high content of pendent functional groups were prepared and characterized by IR, elemental analysis, and thermal analysis. The slight variance of the thermal stability of the resins was related to the kind and content of the pendent functional group. The adsorption capacity of the resins for Mg(II), Cu(II), Co(II), Pb(II), and Hg(II) was determined. Toward Hg(II), the adsorption capacity of the resins was high and the adsorption process was easy and spontaneously performed. The XPS study showed that the adsorption of the NCR-SN resin toward Cu(II), Pb(II), and Hg(II) was mainly the coordinate interactions between the ligand atom (S, N) of the pendent functional groups and the metal ions. (C) 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1457-1465, 2000.