Abstract: In this rscarch, established a method for determination of SO2 residue in grape wine by electric potential titration. The method uses electric potential titrator to evaluated and control the end of point. In designing the method, we use helium to lustrate SO2 in sample which used be a blank control to eliminate the interference of other compounds in wines. The relative standard deviations of the method are between 0.15%～0.67%, the recoveries are between 99.1%～100.7%, the least limit of detection is 0.5 mg/L.

Key words: electric potential titration, sulfur dioxide, grape wine