Graphene has recently attracted many interests in material field due to its unique two-dimensional structure and excellent properties, while graphene/metal composites is one of the most important research frontiers in the application of graphene. A review is provided herein on recent advances in preparation and applications to catalysis, sensor and spectroscopy about metal NPs-on-graphene composites, as well as the research progress about graphene-reinforced metal matrix composites (MMCs) in high strength and high thermal/electrical conductivity region, focusing on the current systems particularly with the excellent performance and the challenges.