A new schiff base based membrane ion selective electrode has been developed. The ion selective electrode system prepared used without an internal solution contains dioctyl phthalate (plasticizer) and sodium tetra phenyl borate (anion excluder). The electrode reveal a Nernstian behavior in linear concentration range of 1M to 1x10-4M with detection limits of the order of 10-4M. The stable potentiometric signals are obtained within a short time period of 1 minute. The effect of pH, and the effect of medium have been studied to found a better response. Selectively coefficient values were evaluated. The sensors have also been used as an indicator electrode in potentiometric titrations of Ca (II) ions with EDTA and determination of concentration of Ca2+ in milk and hardness in water samples.