Nicotinamide phosphoribosyltransferase (NAMPT), also known as pre-B cell colony-enhancing factor (PBEF) or visfatin, is a crucial rate-limiting enzyme of NAD biosynthetic pathway. It may affect the metabolism, inflammatory response, cell proliferation, differentiation, and apoptosis, especially the aging and other physiological progresses through regulating NAD biosynthesis and nonenzyme routes in the organisms and cells. This review mainly focuses on recent progresses in the expression modulation and feedback regulation of Nampt gene.