After Nd-Yag laser treatment with and without water thin film, copper plate material was used under 2880 hours of humidity environment to build a green oxide layer. Oxide layer and water thin film were studied; corrosion rate and oxide percent were measured with and without water film under same environment for one laser pulse, 2 pulses, 3 pulses and 4 pulses. The results show improvement and stability in corrosion rate for water thin film of one pulse during the test period. This paper gives comparative results referring to water laser technology on corrosion rate of green oxide layer for copper plate
with and without water thin film during specific period of time.