Abstract: Poly L-threonine modified glassy carbon electrode was prepared by electropolymerization of L-threonine. The electrochemical behavior of tert-butyl hydroquinone(TBHQ)was studied by cyclic voltammetry(CV). A new method for the determination of TBHQ in food was established. Under the optimal conditions,good liner relationships between current intensities and TBHQ concentrations were obtained in the ranges of 2.0×10^-7~2.0×10^-5 mol·L^-1,with correlation coefficients(r)of 0.9994,the detection limit was 8.6×10^-9 mol·L^-1. The modified electrode can be applied to the analysis of TBHQ in sample with recoveries of 98.5%~102.6%.