Abstract Electronic structure of monolayer graphene with metal contacts can be modified by control of interfacial interaction. Here, we show that the strength of local interfacial interaction between graphene and Au(111) surface can be electrochemically controlled by the hydrogen evolution reaction process. Graphene/Au(111) electrodes were prepared by the chemical vapour deposition. Raman spectroscopy indicated existence of monolayer of graphene over Au surface. Local interaction of graphene/Au(111) interaction can be differentiated by intercalation of H₂ molecules at interface. This study shed lights on the possibility of proton penetration through the graphene to modify the strength of interaction between graphene and Au(111) surface.