The synthesis of the difurylmethane-maleicanhydride(DFM-MAH) copolymer was done by reacting difurylmethane with maleic acid followed by hydrolysis with sodium hydroxide to produce the anhydride sodium salt. Construction of a sensor with the copolymer as the ion-exchanger material was done by mixing the copolymer with poly(vinylchloride), PVC, plastic matrix and dibutylphthalate (DBP) plasticizer in tetrahydrofuran (THF) solvent to form a paste. The paste was coated on a piece of silver wire to produce a coated wire electrode (CWE). The response characteristics of the copolymer-CWE, in potentiometric analysis, were studied for mono-, di- and tri-valent cations. All the cations studied showed a near-Nernstian response for concentrations ranging from 5 x 10 -8 M to 1 x 10°M in triethanolamine buffer in aqueous media (0.5 M, pH 10.5). The membrane had a composition of 20:20:60 for the copolymer, PVC and DBP.