Abstract: The group delays of normal modes in shallow water are obtained by an adaptive time-frequency analysis. The bottom sound velocity and density are inverted based on single hydrophone by matching the group delays of normal modes. Group speeds of mode 1~4 for the inverted parameters provide an excellent match to the experimental data obtained from time-frequency analysis, several inverted parameters include the depth of the water, the depth, density and sound speed of the deposit are reliable, and the processed results indicate that it is a simple, fast and effective approach for geoacoustic inversion.