A novel method of preparing 1-dodecanethiol (DT) self-assembled monolayers (SAMs) on copper in aqueous micellar solution is explored. The resulting SAMs are characterized by XPS, contact angle tests and electrochemical measurements. It is found that DT dissolved in aqueous micellar solution can adsorb rapidly to the copper surface through strong thiolate bonds to form well-organized SAMs, which have properties comparable to those formed in ethanol solution. The electrochemical measurements show that the inhibition efficiency (IE) increases with an increase in the immersion time of copper in the aqueous micellar solution. After self-assembly for 1 h, the SAMs are able to effectively protect the underlying copper against corrosion in chloride-containing solution by hindering the cathodic process. Overall, the inhibition efficiency can reach 98.94%.