Nanomaterials have novel physical and chemical properties as a result of the size-confinement effect. Metal-and semiconductorbased nanocrystals have been proved to be promising floating-gate charge-trapping media for nonvolatile flash memory. Miniaturization of memory devices requires one to reduce the size of such materials incessantly. However, due to the quantized energy levels associated with a size below the quantum limit, the performance of semiconductor nanocrystals is degraded. The instability and the fabrication process incompatibility also limit the development of metal nanocrystals for floating-gate memory. Newly emerging

graphene has attracted much research interest for flash memory materials. Compared with conventional materials, atomic-layerthick graphene is chemically inert and thermally stable; meanwhile it has high electrical conductivity and high carrier mobility and is compatible with the conventional semiconductor fabrication processing. In this chapter, we give an overview of the synthesis, properties, and memory device applications of graphene and related graphene nanosheets. The promising findings as well as the future potential directions of this research field have been highlighted.