In pH 8. 0 solution,the poly( valine acid) modified electrode was prepared using electrochemical method. The electrochemical behavior of tartrazine was studied at the poly( valine acid) modified electrode. A new method for the determination of tartrazine was established. In pH 6. 0 phosphate buffer solution,the current of reduction peak of tartrazine showed a linear relation over the range of 6. 0 × 10- 8~ 2. 9 × 10- 5mol / L. The detection limit was 2. 0 × 10- 8mol / L. The modified electrode operate easily and the detection is rapid and sensitive. The method has been successfully applied for the determination of tartrazine in real food samples.