Abstract: The Renqiu buried-hill oilfield is one of the large and Prolific oilfields in China discovered in the middle of 1970s. This type of oilfields was formed in a specific geotectonic background, which have their distinctive characteristics, and is a klnd of oil-formation assemblages of so-called "younger oil accumulated in older reservoirs",i.e. Cen-ozoic oil generated in geosag stage emplaced into older sub-Sinian and Paleozoic carbonate reservoirs formed in platform stage well developed with fractures and caverns. The pools have a variety of forms and are distributed regularly, resulting in the occurrence of multiple oil and gas accumulation zones. This paper discusses emphatically the formation of the oilfield in light of the geotectonic background, which provides informations significant to the search of oil and gas.