Abstract: A graphene transfer method using water vapor-assisted determination of CVD-grown graphene film on the Cu foil. By using the polymer film as a supporting layer, we found that graphene can be directly detached from the Cu foil as a consequence of water intercalated at the graphene-Cu interface(s), by a ‘dry transfer’ method. The delaminated graphene films are continuous over large area. This nondestructive method also worked for the transfer of graphene grown on a Cu single crystal without sacrificing the expensive crystal, thus affording the possibility of producing high-quality graphene and reusing the substrate. The Cu foil and single crystal can both be repeatedly used for many times, which may reduce the cost of graphene synthesis and is environmentally more benign. Our method affords the advantages of high efficiency, likely industrial scalability, minimal use of chemicals, and the reusability of the Cu foil in multiple growth and delamination cycles.