Abstract: The viewpoint that Guantao Formation of Neogene in Jiyang depression developed alluvial facies has been for a long time，in this research，by means of core observation from continuous coring wells and such analytical information as well data，well logging and paleontology，as well as the application of sedimentology theory，the sedimentary viewpoint that the formation developed only alluvial facies is nodified and enriched，it is recognized that at the lower section of the formation develops not only rudaceous braided river sedimentation，also braided river delta-infilling shallow lacustrine sedimentary system，at the begining of late Guantao period developed，braided and meandering river deposition developed，and at the mid-late stage of the late period，shallow water delta-oxidizing shallow water lacustrine and shallow oscillating lacustrine depositional system developed.In beds correlation and hydrocarbon exploration tightly related to oilfield production，the lacustrine sedimentary facies model is widely used.

Key words: Gudao Oilfield, Guantao Formation, sedimentary facies, depositional system