Polyaniline supported Ti(IV) arsenophosphate [PANI Ti(IV) AsP] composite cation exchange material was synthesized by a simple chemical route. To explore the application of this composite material, a lead ion selective membrane electrode was fabricated. The composite membrane electrode demonstrated a Nernstian response of 29.3 mV per decade change in concentration of Pb2+ ions over a wide concentration range (1 X 10(-1-)1 X 10(-6) M) with a detection limit of 1 X 10(-6) M. Mixed solution method was used to determine the selectivity of Pb2+ ions in the presence of interfering cations. The practical utility of PANI Ti(IV) AsP membrane electrode has been fruitfully explored by using it as an indicator electrode for potentiometric determination of lead.