Abstract: In order to obtain the seabed acoustic characteristics as efficiently as possible,a single parameter inversion method in frequency domain is proposed by reducing the dimension of inversion parameters,and this method could be applied to the classification of seabed sediments.Based on the single parameter seabed model,correlation processing of the seabed reflected signal is carried out in frequency domain,and the relationship between seabed single parameter and frequency displacement when the normalized frequency-domain autocorrelation coefficient decreases to 0.5 is derived by the geometric ray theory.By studying the equivalent relationship between single parameter and sediment types,the seabed sediments are classified.Combined with the experimental data of Baltic Sea in Poland,the seabed single parameter in the frequency band of 1000~2500 Hz are inverted,and the type of seafloor sediment is very fine sand.The results show that the predicted sound transmission loss with inverted single parameter is in good agreement with the experimental value,and the seabed sediment type obtained by the inversion results are consistent with the sampling results.It is proved that the classification results are correct and the inversion method in frequency domain is effective.