Abstract: Graphene is a two-dimensional semi-metal with zero bandgap and has been receiving considerable attention from both academia and industry. In this review we summarize the synthesis methods of graphene and classify them into three categories: solid, liquid and vapor states. The structure, defects and electrical, optical, thermal and mechanical properties of graphene are then discussed. The applications of graphene mainly focus on electronic and electromechanical devices, separation membranes, and templates/substrates.