Abstract: Wide-angle echo data of submarine sedimentary beds are collected by a system composed of a seismic profiler and a hydrophone streamer towed behind the profiler.Usually the wide-angle echo data ale processed with common-depth-point stack method to obtain the stached section for geological interpretation.When the acoustic velocity of the sedimentary layers has a lateral variation,the stacked section does not represent the real structure of sedimentary layers.Based on this stacked section,we would probably draw a false conclusion.In case of knowing the acoustic velocity of sedimentary beds we may remove the distortion caused by acoustic velocity lateral variation from the stacked section with acoustic wave equation Kirchhoff integration which continues the wavefields in downgoing and upgoing directions respectively.Thus the accurate image of the structure of submarine sedimentary layers is obtained