The modification ot benzidine on the surface of industrial pure iron was investigated with regard to its technology and method. The anti-corrosion performance of modified film in various solutions was discussed by using some electrochemical techniques. The surface composition and structure of modified film were analysed by Auger electron spectroscopy

Fourier transform-infrared spectroscopy and X-ray diffraction. The research results showed that the modified film had good anti-corrosion performance in weak acid

neutral solution containing Cl- and strong alkali. The protection mechanism of modified film was also discussed.