Formation pressure measurements and logging and seismic data were combined with basin sedimentary texture to analyze the spatial distribution of formation overpressure and its controlling factors.The results show that 1) overpressure zone is widely distributed in the central part of the basin.It has a diachronous top surface

shallows overall in NW direction and deepens toward the centre of the sag.In Mosuwan area

the top surface of the overpressure zone corresponds to the Jurassic Sangonghe Formation and has a burial depth of about 4 400 m.In Xiayan-Dabasong and the Mahu areas to the west

it corresponds to the Triassic and shallows to 3 500 m.In an oil field called Yongjin in Munan uplift

it corresponds to the bottom of the Cretaceous and deepens to about 5 800 m. 2) Overpressure can be observed in layers at and below the Jurassic in Mosuowan area with the highest values measured in the Jurassic and some lower values measured in the Permian-Carboniferous.Two types of overpressure are classified based on profile characteristics of pressure coefficient structure. 3) Spatial characteristics of the overpressure anomalies in central Basin reveal the roles of different controlling factors upon the forming of overpressure in different tectonic locations in the basin.