Abstract: A PVC membrance SO₂^-4ion-electrode made up of a electroactive substance and plasticiser,was reported in this paper.The electroative substance was composed of 2-Aminperimidine and SO₂^-4.The plasticiser was made up of DBP.The experiment made clear that the ion-electrode had good selectivity and high sensitivity about SO₂^-4.The electrode gave a linear response range from 5.0×10^-7 mol·L^-1 to 1.0×10^-1mol·L^-1.This electrode has been used for determining SO₂^-4 in water.The result was satifactory.

Key words: Sulfate, ion-electrode, 2-Aminperimidine