The effect of receive field of view (FOV) on laser sounding echo signals is analyzed based on“multipleforward scattering and single-backscattering”laser sounding echo signal mathematical model. The relationship between the FOV loss factor and the receiver FOV is discussed under different depths. D -index of discriminability of airborne laser bathymetric system is served as a performance evaluation criterion and the relationship between it and receiver FOV is analyzed. Further, the optimal FOV for different maximum detection depths is derived. The result in this paper can contribute to the optimization of FOV of airborne laser bathymetric system. Thus theoretical basis for the development of new airborne laser bathymetry system is provided.