Abstract：Guided by sedimentology and seismic stratigraphy and integrative application of geologic, seismic and logging information, the paper carried out detailed study of seismic-geologic facies model for sandy-gravel fan on northern steep slope zone of Chezhen sag and talked about the concrete method and process: first the frame model of sandy-gravel body is built up based on the relationship between the wave impedance and lithologic facies, then the velocity analysis, model-fractioned and time-to-depth conversion are carried out for the model and finally the fan is gotten by forward simulation. The application results showed this is a set of feasible model-building method of complex geologic body. It's considered by deep study of fan model in the region that the cutoff, branching and distortion of target events in the region do not result from the fault, but lithologic change.
