Plasticized membrane using 5,6:17,18-dibenzo, 11,12-(4-nitrobenzo)-2, 3-bis(hydroxyimine)-7, 16-dithia-10, 13-dioxo-4, 19-diaazacyclooctadecane (N2S2O2) based ionophore has been explored as Ag+ ion-selective sensor. Optimum performance is observed with membrane having composition of PVC, plasticizer and ionophore in the ratio of 33:65:2(wt. %). Stability constants for different metal ions have been determined by conductometric titrations. The sensor works satisfactorily in the concentration range of 2.5x10(-5) to 1.0x10(-1) M(detection limit 7.9x10(-6) M) with a Nernstian slope of 58.5 mV/decade of activity. Wide pH range (5.0-9.0), fast response time (15 s), non-aqueous tolerance (up to 30%) and adequate shelf life (3 months) indicate the vital utility of the proposed sensor. The proposed sensor. The proposed electrode shows good selectivity for Ag+ ion with respect to alkali, alkaline earth, transition and rare earth metal ions and can be used for its determination in binary mixtures. Determination of chloride contents in samples of Vitamin B-1 and tap water has also been made by using the proposed electrode.