Abstract: Based on the principle of statistical energy analysis for non-conservatively coupled dynamical systems under non-correlative or correlative excitations, energy relationship between two similar SEA systems is established in the paper. The energy relationship is verified theoretically and experimentally from two similar SEA systems i.e., the structure of a coupled panel-beam and that of a coupled panel-sideframe, in the cases of conservative coupling and non-conservative coupling respectively. As an application of the method, relationship between noise power radiated from two similar cutting systems is studied. Results show that there are good agreements between the theory and the experiments, and the method is valuable to the analysis of dynamical problems associated with a complicated system from that with a simple one.