Miniaturization is the central theme in modern fabrication technology. Following the introduction of nanofabrication and its significance the two major nanolithographic processes using electron and ion beams are first addressed. These processes are similar to the conventional photolithography by using energetic beams for pattern transfer to the target substrate. Subsequently, the lithographic techniques of nanoimprinting and scanning probe microscopy (SPM) are evaluated with the emphasis on their lithographic abilities and applications. Three major schemes in the family of SPM lithography, including (1) scanning tunneling microscopy, (2) atomic force microscopy, and (3) dippen nanolithography, are separately presented. The principles and associated procedures of these three schemes are discussed first and the differences among them are then elaborated. The bottom-up strategies for nanofabrication are also reviewed. Self assembling with and without externally controlled forces for patterning nanoscale structures has been examined. The associated principles and procedures of key assembling processes are given. Application examples for several self-assembly techniques are also included. Finally, the prospective areas for future research in nanofabrication are presented.