Objective To study the anti-corrosion performance of aniline homopolymer / epoxy composite coating and aniline copolymer / epoxy composite coating in 3. 5% NaCl solution. Methods Chemical oxidation polymerization method was adopted to prepare aniline homopolymer and copolymer. The polymers were characterized by SEM, XRD, UV-vis and IR; the anti-corrosion performance of composite coating in 3. 5% NaCl solution was analyzed by electrochemical test. Results Aniline homopolymer / epoxy composite coating and aniline copolymer / epoxy composite coating both had different levels of anti-corrosion effect. In contrast, the aniline copolymer / epoxy composite coating had the highest corrosion potential and the lowest corrosion current density. Conclusion Aniline copolymer produced a layer of passivation film on the surface of carbon steel, granting the aniline copolymer / epoxy composite coating with good anti-corrosion performance.