Abstract: The integrated seismic and geological interpretation technology is now widely used in seismic interpretation. The key of the technology is to make integrated seismic interpretation under the guidance of a geologic thinking. Geological models are adopted to constrain the multiple solutions in seismic interpretation, and the accuracy of seismic technology is fully used to constrain the wide possibility of geological interpretations. Taking the structure JZ20-A in the Bohai Sea as an example, we made detailed early evaluation of reservoir using the integrated seismic and geological interpretation technology, based on fine trap description and reservoir prediction. Close integration of seismic technology and geologic model is used in definition of a geologic body.