The catalytic electro-oxidation of hydrazine by H2TMAP and CoTMAP has been investigated. The kinetic parameters of the electrode reaction were measured and the reaction mechanism for the electro-oxidation of hydrazine in the presence of H2TMAP and CoTMAP is proposed. The electrocatalysis of the porphyrin ring, a novel kind of electrocatalysis of metalloporphyrins, is discussed.