MXene is a new family of two-dimensional transition metal carbides or carbonitrides with graphene-like 2D morphology. The chemical formula of MXene is Mn+1XnTz, where M is an early transition metal, X is C and/or N, T stands for surface-terminating functional groups like F-, OH-, O2-, etc., and n = 1, 2, or 3. It can be achieved by selective etching of the A element from the MAX phases, and HF is an etchant mostly used. First-principles calculations about MXene have been performed to reveal the structure and properties. MXene has also been found to have a unique two-dimensional layered structure, large specific surface area and good electrical conductivity, stability, magnetic and mechanical properties, and thus it is promising in many fields, including energy storage, catalysis and adsorption. This article reviews the quite recent progress of MXene based on theoretical and experimental considerations, especially its structure, synthesis, and applications. Finally, the suggestions about existing challenges and future developments are proposed. MXene is expected to be used for more various applications with further extensive research.