By using cyclic voltammetry,eosin Y film was electrodeposited on the surface of glassy carbon electrode(GCE) to obtain the modified electrode(denoted as eosin Y/GCE). The electrochemical properties of eosin Y/GCE were studied by electrochemical impedance spectroscopy.The electrocatalysis capability of eosin Y/GCE to tertiary butyl hydroquinone(TBHQ) was investigated by cyclic voltammetry(CV) and differential pulse voltammetry(DPV) .Compared with the bare GCE,eosin Y/GCE exhibited outstanding electrocatalytic activity and reversibility towards the oxidation of TBHQ.The oxidation and reduction peak separation was decreased from 297 mV to 85 mV for TBHQ at eosin Y/GCE.Influence of different scan rates(20-400 mV?s-1) on redox of TBHQ was further examined at the eosin Y/GCE.The oxidation and reduction peak currents were linear to the square root of scan rate,indicating that the diffusion controlled process of TBHQ occurred at the eosin Y/GCE surface.Under the optimal conditions,the DPV response of the modified electrode was linear to TBHQ concentration in the range of 1-200 μmol?L-1 with a detection limit of 0.1 μmol?L-1.Moreover,eosin Y/GCE exhibited excellent selectivity,reproducibility and long-term stability,and was successfully applied in the determination of TBHQ in soybean oil samples with recoveries of 95.0%-102.5%.This modified electrode could be used as a promising sensing platform for the determination of different antioxidants in food samples.