Abstract: A 3D shallow-water normal-mode reverberation model is derived. The model is used to calculate the acoustic energy propagating from the source to the scattering area,and from the scattering area to the receiver. In the scattering area,the influence of the complex eigenvalues and the effective normal-mode wave on the incident wave and reverberation is discussed. The normal-mode wave is decomposed into up-going and down-going waves. By down-wave and the Lambert scattering law,the receiving reverberation intensity by scattering of bottom in the shallow-water is in accordance with the receiving data of monostatic hydrophones. The form of reverberation model is simple,which has clearly physical meaning and general applicability.