Summary on emergence of complex systems

As a science concept, emergence is used to describe the modes and structures or properties of complex systems, it is also an essential characteristic of complex systems. The paper recalls all kinds of definitions of emergence in the literatures, summarizes the properties and criterions of emergence, and expatiates the emergence mechanism and theoretics for researching. On the basis of it, definition and mechanism on emergence of complex systems are given, some control methods are proposed. Finally, it evaluates the significance of emergence and prospect of the subject.