It has been carried out a study of the acoustic resonance backscattering produced by a hollow elastic sphere submerged in water. It has been studied the effect produced by the material and by the thickness of the hollow sphere, on the maximum target strength reached at the resonance frequency. Also the effect produced on the bandwidth of the resonance frequency has been evaluated. The principal application of this work is to develop a target, easily detectable by its very high target strength. It is of main interest to work at the usual frequency band of the echosounders and fishering sonar.Peer reviewed