Abstract: Based on wave transfer propagation theory in infinite layered medium,sound insulation performance for underwater compound damping structures(basic materials are rubber and steel) is investigated using transfer matrix method and percentage distribution of sound energy in certain area.Simulations show that the property of rubber material influences sound insulation of structure greatly.Soft rubber as well as those with small Poisson's ratio may improve sound insulation performance of the whole structure remarkably.Multi-layered rubber compound structures outperform mono-layered ones.It's a good way to make cavities inside multi-layered rubber compound structures for improving sound insulation property.The more the cavities are,the better sound insulation will achieve.As a particular kind of complex multilayered rubber compound structures,honeycomb sandwich rubber compound structure has better sound insulation property than rubber interlayer with cylindrical cavities compound structure and homogeneous rubber compound structure.To confirm theoretical analysis,many measurements of freedom-field of honeycomb sandwich compound structure have been carried out in anechoic water tank.The measurement results have good agreement with theoretical prediction.