The use of modern state-of-the-art device fabrication techniques and the development of new methods of nanosclae material synthesis/manipulation enable us to investigate at the mesoscopic scales. In these length scales the nanoscaled materials have exhibited a variety of unique physical phenomena due to the enhanced quantum confinement of electrons in reduced dimensions. In this presentation, we will discuss our recent investigation of mesoscopic transport phenomena in carbon nanotubes, nanowires, and a single atomic layer systems such as graphene, where quantum mechanically enhanced low dimensional effects are predominant. Employing electric field effect from the gate electrodes, we can control the carrier density in these materials which control the transport properties. The subjects include, (1) growth/manipulation of ultralong nanotubes and electrical characterization of them, (2) electric field effect in mesoscopic thermoelectric transport in nanotube/nanowires, (3) 1D to 3D cross-over in electric transport in multichannel nanowires, and (5) electric field-effect control of novel 2D systems obtained from layered materials including graphene and other thin atomic layer crystals.