Abstract: The reason for formation overpressure was analyzed.Interval transit time and seismic velocitywere used in formation pressure prediction and the theoretical basis was introduced.Through researchand application,the advantages and disadvantages of different methods were compared.Formation pres-sure prediction technology was practiced in the Tahe Oil Field,and proved correct and effective.Theequivalent depth method and the method proposed by Bowers were sensitive and inverse correlative toformation velocity,both serving well for prediction.The prediction method using seismic velocity couldsimply predict the changing trend of pressure of big formation.In wild-cat area,the seismic velocitymethod was used to predict pressure before drilling,improving drilling productivity and supporting safedrilling.