Abstract: Sodium sulfide is widely used in mineral processing,which is not only the vulcanizing agent for the some metal oxide ore,but also the inhibitor for sulfide mineral flotation..In this paper,the REDOX reaction process of sodium sulphide was studied under the condition of alkaline by electrochemical method on Pt electrode.Results show that there is neither sulfurous acid in the solution of sulfuric acid root ion nor sulfur generation ion also its re action,but sulfuric acid root ion in the solution.