A completely new concept about the kinematic chain, called the link’s adjacent-chain table (shortened as ACT), is originated in this paper. It is an invariant which can be used to describe the topological relationships between links in the kinematic chain (shortened as KC). In comparison with the traditional representation of the KC, i.e. with the adjacent matrix, link’s ACT is much more audio-visual and simpler. Using the link’s ACT, the isomorphism of the KC can be easily determined. Among the existing methods for the identification of the isomorphic graphs, link’s ACT takes the least time in calculation. So it’s introduction of the link’s ACT leads to a effectual solution to identify the isomorphism of the KC.