This book highlights a comprehensive introduction of graphene and graphene-based two-dimensional nanomaterials, covering topics from their atomic structures, electronic band structures, and fundamental properties to technological applications. The book provides fundamental physics knowledge covering quantum mechanics, the theory of relativity, solid-state physics, and topology geometry necessary to understand electronic band structure of graphene. Other topics including microscopy techniques and preparation methods of graphene are also presented. Adopting an easy-to-read style, the book is a valuable resource for researchers in physics, chemistry, materials science, and engineers who are interested in the field of graphene-based nanomaterials.