Abstract: Electrochemical polarization measurement and electrochemical impedance spectroscopy(EIS) were used to study the corrosion inhibition effect of 1-dodecanethiol on copper in 3% NaCl solution.The results showed 1-dodecanethiol had better corrosion inhibition effect on copper.The corrosion inhibition ability of 1-dodecanethiol was decreased with the adding of benzotrizole, while the same degree of corrosion happened without benzotrizole when pH value of the media decreased to about 1.0.The above corrosion inhibition behavior was supported by SEM.