Statistical energy analysis is a widely used high frequency vibro-acoustic analysis tool. It is based on power flow balance between subsystems. Its accuracy mainly depends on precise determination of energy loss factors. In the paper, three different types of composite structures (point-connected I, L and T types) made of laminated plates are of concern to determine in-situ energy loss factors by using power injection methods (PIM). The results are compared with those obtained by approximate analytical determinations, thus accuracy of numerical and experimental PIM is discussed for point-connected composite plates. Analytical loss factors are computed by an iterative procedure to consider indirect coupling for the structures having more than two subsystems. (C) 2015 Elsevier Ltd. All rights reserved.