Abstract: An acid fuchsine modified electrode is used to investigate the electrochemical behavior of L-epinephrine(EP) by cyclic voltammeter. After the optimization of several working conditions, including the supporting electrolyte, pH of the solution, amount of the modifier. and scanning speed and potential, the current of EP at a modified electrode was 9 times as much. Compared with the bare glassy carbon electrode, the current increased linearly with the concentration ofEPin the range of 2.0×10^-5~2.2×10^-3 mol/L with a correlation coefficient of 0.990 9. The detection limit was 9.58×10^-5 mol/L. For eleven repeated measurements of 1.0×10^-3 mol/L EP, a low relative standard deviation of 5.4% was obtained. This method was successfully applied to the determination of EP in injection of epinephrine chloride with a good recovery between 96.1% and 113.0%.