Abstract:Mis-ties at tie points of two-dimensional seismic sections bring big influence upon the interpretation accuracy of two-dimensional seismic data, people usually paid more attention to the mis-tie which results from weathering layers, but neglected that due to stack velocity discrepancy in multifold seismic data processing. It is illustrated that stack velocity discrepancy not only causes the mis-tie which lowers the accuracy of seismic structural map but also leads to variations of waveform, frequency and amplitude which harm lithologic interpretation. Hence, people should think highly of this problem.