Abstract: A method for extracting seabed feature parameters is proposed based on the angular response curve of the multibeam backscatter strength. Based on the change rule of backscatter strength for one ping，the determining method of the number of the pings has been put forward which was inchided in the obtaining of the angular response curve of the mean backscatter strength. The relationship between angular response curve and seabed is analyaed，and using norrleast squares fitting method combine Hellequin parameters model to extract seabed feature parameters. The results show that the extracted feature parameters can suppress backscatter strength error and reserve change information of backscatter strength with incidence angle，and improve capability and reliability of multibeam seabed classification.