The cyclic voltammograms (CVs) and current-time curves of methanol electro-oxidation, assisted by K2FeO4, decomposed K2FeO4 and Fe(NO3)3 added in strong alkaline solution, were investigated on a Pt electrode. The results show that Fe(NO3)3 and K2FeO4, especially decomposed K2FeO4, can promote the activity and poisoning tolerance of a Pt electrocatalyst for methanol oxidation in alkaline solution. We propose that iron(III)-containing compounds such as Fe(OH)3 and FeOOH in a strong alkaline solution tend to encourage the formation of OH adsorption (OHads) species, which are necessary for the promotion of the CO-like intermediates of oxidation on the Pt electrode.