Abstract: The Sudeerte buriedhills are very important reservoirs in the Hailaer Basin. The best reservoirs are generally developed on top of the Triassic metamorphosed siliciclastic rocks called Budate Group and with a thickness from several tens to over 100 meters. The socalled bimedia pore spaces composed of pore and fractures are the prevailing reservoir types with mean porosity of 5.0% and permeability of 0.03×10^-3μm². Two genetic types of the buriedhills can be recognized, faulted block and weathered peleouplift. With southwards subduction of the MongoliaOkhotsk plate north of the studied area during Triassic to early Cretaceous, the Hailaer Basin suffered uplifting and weathering, secondary burying and block faulting, volcanism and fluid alteration, which constructed the buriedhill reservoirs there.

Key words: Hailaer Basin, Sudeerte area, clastic buriedhill traps, hydrocarbon reservoirs