Graphene/metal nanocomposite powder and a method of preparing the same are provided. The graphene/metal nanocomposite powder includes a base metal and graphenes dispersed in the base metal. The graphenes act as a reinforcing material for the base metal. The graphenes are interposed as thin film types between metal particles of the base metal and bonded to the metal particles. The graphenes contained in the base metal have a volume fraction exceeding 0 vol % and less than 30 vol % corresponding to a limit within which a structural change of the graphenes due to a reaction between the graphenes is prevented.