The assembling behavior and corrosion inhibition of docecanethiol SAMs on pure copper surface were investigated by potentiodynamic polarization, impedance spectroscopy and cyclic voltametry. The results show that dodecanethiol SAMs prevent electrons pass through electrode/solution interface and block the contact between corrosion ions and metal surface, the SAMs have obvious inhibition effect on pure copper; The SAMs are more complete, and it’s inhibition efficiency increases with assembling time.