Abstract: Viscoelastic layers have bought favorable damping properties for viscoelastic composite structures, but weaken the strength of the composite structure. It is our desire for the composite structures to satisfy the actual need of both strength and damping property. Based on higher-order displacement mode, mathematical models were built for loss factor and strength. The optimal design of single-objective and multi-objective was investigated for the materials. The results shown that the modified genetic algorithms was available for optimization design of loss factor and strength, and the multi-objective optimization could be comprehensively considered and evaluated for the damping and strength properties of composite structures.