With the development of the oil and gas exploration, it is gradually recognized that the formation pressure has important effect on the hydrocarbon preservation and individual well deliverability. So it is necessary to quantitatively predict the formation pressure based on the seismic data. The prediction method of abnormal formation pressure widely applied now is based on the effective stress theory which is proposed by Terzaghi in 1923 and plays an important role
in civil engineering practice. However, the effective stress theory has limitations in the porous medium which has complex structure. Considering the rock physical properties and mechanics equilibrium principle, we developed a new pressure prediction method based on the dual effective stress of porous medium through the introduction of dual effective stress equation related to porosity, making closer relationship among the overburden pressure, formation
pressure and rock skelecton stress. We achieved good effect after putting this method in practical use to the formations in Mahu slope area, northwest of the Junggar Basin, through the analysis of the genesis of abnormal high pressure andconstrained by the geological origin.