▎ 摘　　要

Graphene nanoribbons are fundamental components to the development of graphene nanoelectronics. At the nanoscale, electronic confinement effects and electronic edge states become essential to the properties of graphene. These effects depend critically on the ribbon width and the nature of the ribbon edge, the control of which at the atomic scale is a major challenge. Graphene nanoribbons have been largely studied theoretically, experimentally and with the perspective of electronic applications. We review the basic properties of graphene nanoribbons and recent progress in fabrication processes, focusing on the question of the electronic gap. We examine top-down and bottom-up approaches to fabricate graphene nanoribbons by lithographic, catalytic cutting, chemical assembly and epitaxial growth methods and compare their electronic characteristics.