The electrochemical impedance spectroscopy(EIS) was used to study the electrochemical corrosion behavior of twelve coating systems including four primer, epoxy intermediate coat and polyurethane topcoat. The evolution of impedance spectra of the four primers immersed in sodium chloride solution was investigated. The protective properties of the primer, the impedance of the two layer system and the impedance spectra of three layer composite system after different periods of immersion were compared based on the study. The results indicate that the protective properties of three layer composite system was better than that of two compound system, while that of the single coating system was the worst. The protective properties of three layer composite system with anticorrosive epoxy coating is the best among all the systems. Paint finish and intermediate coating play the role of isolation from the outside medium and protection of the primer in the coating system based on the characteristic of the electrochemical impedance spectroscopy. The electrochemical impedance spectroscopy can be used to research the corrosion resistance of coating systems.