4-Aminopyridine is an important fine chemical. To investigate the electrochemical synthesis mechanism of the 4-aminopyridine, the electrochemical behavior of 4-nitropyridine-1-oxide under the strong acid conditions was studied by cyclic voltammetry, controlled potential coulometry and some other methods. 4-Hydroxylaminopyridine-1-oxide was produced when 4-nitropyridine-1-oxide mainly went through the electrochemical-chemical-electrochemical (ECE) process on the platinum electrode. As far as the copper electrode was used, the potential should be higher than －0.65 V to go through the ECE process, and 4-hydroxylaminopyridine-1-oxide was produced. When the electrode potential was lower than －0.85 V, 4-hydroxylaminopyridine-1-oxide could be reduced further to 4-aminopyridine after another 4e^－ transfer on the copper electrode.

Key words: 4-nitropyridine-1-oxide, 4-aminopyridine, electrochemical reduction