Depth retrieval method for airborne laser bathymetry is discussed. The corrected method using sea wave and tide and the non-corrected method using KGPS-OTF are introduced. The facts affecting the depth error in airborne laser bathymetry are analyzed. The depth retrieval errors of airborne laser bathymetry using the two methods are evaluated. The accuracy from the corrected method is little higher than that from the non-corrected method, while the non-corrected method is more simple and fast for data processing.