Abstract: Finite element model(FEM) of the embedded co-cured perforated damping layer composite structure (ECPDLCS)was developed, and the improved mode strain energy method to predict the mode loss factor was presented. The FEM simulation results were verified by experiment data, which indicates the method and model proposed by this paper was valid. The valid model and method was employed to investigate the effects of the damping layer thickness, punch diameter and spacing on the mode loss factor and natural frequency of the embedded co-cured perforated damping layer composite structure. The impact of punch diameter and spacing on dynamics characteristics in the same damping layer area ratio was also explored. The result shows that the increasing of damping layer thickness and reducing of diameter and/or spacing can enhance mode loss factor, however the mode frequency is decreased. Under the same damping layer area ratio, the mode loss factor is rose and the mode frequency is decreased with the increasing of diameter and spacing. The conclusion is very important for the theoretical prediction of the dynamics characteristics of the ECPDLCS.