Metamorphic mechanisms make continuous development and innovation in theoretical and practical aspects along with the in-depth research focused on this kind of mechanisms.It is important to summarize and analyze the existing research results and make prospects to the future development trend,so as to promote the further development of theories and applications of metamorphic mechanisms.The origin and significance of metamorphic mechanism are introduced with respect to the current progress.Criteria for the classification of this kind of mechanisms and the approaches for implementation of metamorphosis are identified.The fundamental basis of metamorphic mechanisms is addressed in accordance with the design,kinematics and dynamics,as well as the compliant metamorphic mechanisms.The well developed topological representation,structure analysis and synthesis are summarized and the prospective applications of the metamorphic mechanisms in space exploration,modern manufacturing and robots are addressed.The potential research directions of metamorphic mechanisms are proposed.