Abstract: Since the discovery of graphene in 2004, two dimensional (2D) layered functional materials featuring weak intra-plane bonding and strong inplane covalent bonding have inspired tremendous amount of research interests in both the industries and academic institutes over the past years. These 2D materials, which can be usually achieved by (1) mechanically exfoliating or liquid exfoliating layered structural materials to produce single and/or few layer nanosheets; (2) chemical synthesis approaches; (3) Langmuir-Blodgett method; (4) layer-by-layer self-assembly; (5) chemical vapor deposition; (6) molecular beam epitaxy and (7) atomic layer deposition technology as well, have found many potential applications in the fields such as field-effect transistors, optical modulators, mode-locked and Q-switched lasers, optical limiters, information and energy storages, radio frequency devices and chemical sensing due to their unique structural characteristics and superior properties. Taking graphene as an example, as the thinnest material ever known in the universe, graphene exhibits a range of unique properties, viz., high three-dimensional aspect ratio and large specific surface area, superior mechanical stiffness and flexibility, remarkable optical transmittance, extraordinary thermal response and excellent electronic transport properties, promising its potential applications in electronics, optoelectronics and photonics. Besides graphene, the other 2D materials including graphyne, borophene, germanene, hexagonal boron nitride, transition metal dichalcogenides (TMDCs), graphitic carbon nitride, layered metal oxide, 2D polymers, metal organic framework, perovskite, and black phosphorus as well, have also been widely explored in recent years. Design and preparation of novel 2D materials and their organic/polymeric derivatives are a key issue for exploring more applications of them, which would most likely be driven by breakthroughs in chemistry of 2D materials that combine the economy of scale with function in the near future. This review summarized the basic concept and their research progresses of 2D materials. The key problems that need to be solved urgently and their development trends in the near future have also been discussed in detail.