Abstract: The formation and distribution of lithologic-stratigraphic traps are dependent on the geological structural background, space distribution of strata, special deposition environment of the basin, and the effect of later structure events. With the theory of sequence stratigraphy and seismic stratigraphy, it analyses the various types of lithologic-stratigraphic traps, their occurrence conditions and the exploration difficulty, and also proposes the exploration thinking that builds in the basement of finding out "three surfaces and one line" (i.e. maximum flooding surface, initial flooding surface, unconformable surface and pinchout line) in oil-rich sags and the suggestions that include mapping for lithologic-stratigraphic traps and checking the interpretation quality in the term of lithologic-stratigraphic traps. The suggestion is not only helpful for mapping standardization of lithologic-stratigraphic trap, but also to promote deepening the interpretation of lithologic-stratigraphic traps and discover more promising lithologic-stratigraphic oil reservoirs.