The back scattering or forward scatter ing (water scattering signal) echo is str onger than or equal to the ship wake signal,which makes signal detection and pro cessing very difficult.Therefore,we present an effective laser ship wake detection method.Fr om this method,there are obvious differences in the depolarization characteristics.When linearly polar ized laser is used to detect the no bubble water and the water with large amount of bubbles,this method can distinguish the water scattering signal and ship wake signal.In this paper we can get depolarization characteristics from differ ent size bubble populations under different detection positions and detection angles.From the further experimental investigation,we can get that this method is both suitable for the forward scattering and backward scattering detec tions as bubble size in the range of 10－150μm;when bubble size is larger than 150μm,this method is only suitable for the forward scattering detection by laser.Water scattering signal and ship wake signal are much more d ifferent by this method. Experimental results illustrate that the water′s back scattering or forward sca ttering echo can be effectively eliminated,and the ship wake signal and water scattering signal can be extracted with this meth od.This method can greatly improve the ability of the ship wake detection.