Abstract: Anew strychnine-selective liquid membrane electrode made with strychnine-tetra (m-methylphenyl) borate ion-pair complex is developed. The electrode shows Nernstian response down to 5×10^-6 M strychnine solutions with a slope of 56mV/concentration decade, and better selectivity than previously published one. Rapid and accurate methods for direct potentiometry or potentiometric titration of strychnine in pharmaceutical preparations are suggested.