Abstract: For oil and gas prospecting, the focal point of our work has already been transferred from the stage of mainly searching for structural traps to that of searching for stratigraphic and lithologic traps. To aim directlyat the ability of seismic survey in ntnoiogic oll-gas exproration ,the au thor made a special examination of the basic geologic conditions, or, in other words, the geologic prerequisite, of such kind of survey. Based on the examination, it has been pointed out that the polycyclic tectonic movement and the existence of various kinds of sandstone are the basic conditions of forming the stratigraphic and lithologic traps and just because the acoustic property difference between sandstone and mudstone is big enough, this made it possible for us to carry out the sandstone trap exploration and the oil-gas direct detection in Bohai Gulf Basin.