Electrochemical oxidation mechanism and voltammetric detection of bisphenol A（BPA） mediated by ［Fe（phen）3］2+（phen=1,10-phenanthroline） on an indium-tin oxide（ITO） electrode in sodium dodecylsulfate（SDS）-ethanol-water systems were investigated by means of cyclic voltammetry and differential pulse voltammetry.［Fe（phen）3］2+ showed a good electrocatalytic activity for BPA oxidation,depending on ethanol-to-water volume ratio,SDS and BPA concentrations.In the ethanol-water（1∶5） system,the addition of 0.25 mmol?L-1 SDS could facilitate the electrocatalytic oxidation of BPA by ［Fe（phen）3］2+ on the ITO electrode.In the ethanol-water（1∶5） system containing 0.25 mmol?L-1 SDS,a significant electrocatalytic oxidation peak at ca.0.731 V was observed in the DPV curve,and its peak currents were linear for BPA concentration in the range of 0.2 - 20 μmol?L-1（r=0.999 9）.The detection limit（S/N=3） of BPA is 0.034 μmol?L-1 and the relative standard deviation（RSD,n=3） is 2.1%.The proposed method was successfully used to analyze BPA in water samples with recoveries of 96.9%-100.7%.The electrochemical oxidation mechanism of BPA mediated by ［Fe（phen）3］2+ in the SDS-ethanol-water system was also discussed.This study not only helps us better understand the electrocatalytic oxidation mechanisms of phenolic pollutants by redox mediators in microemulsion systems,but also provides a new idea for the fabrication of electrochemical sensors.