Corrosion protection of steel coated with chlorrub resin containing polyaniline has been studied in 3% NaCl by electrochemical impedance spectroscopy (EIS). Polyaniline was prepared by oxidative polymerization of aniline using ammonium persulphate in HCl medium. Using the synthesized polyaniline, paints were prepared using chlorrub resin with 1, 3, and 5% polyaniline. The variation of resistance and capacitance of the coating with time has been found out be EIS. The study has shown that the polyaniline content of 1% is able to offer sufficient protection of steel in neutral media and usage of higher percentage of polyaniline does not have beneficial effect. (c) 2006 Wiley Periodicals, Inc.