Abstract: The vertical correlation of shallow water reverberation is an interesting topic in the research of shallow water acoustics. The vertical correlation of shallow water reverberation was discussed based on the ray-mode reverberation model. A concise analytical expression for the vertical correlation of reverberation in isovelocity shallow water was derived. The relationships between the vertical correlation of reverberation with the reverberation time, frequency, source depth, receiver depth, bottom reflection loss, and bottom scattering coefficient were also discussed by the numerical calculation and experimental data. The results show that the vertical correlation of shallow water reverberation is independent of source depth based on the separable bottom scattering model, and it increases when reverberation time and bottom loss increase, or frequency, receiver separation, and water depth decrease.