1． College of Geo- Exploration Science and Technology，Jilin University，Changchun 130026，China; 2． Drilling Division，CNPC Offshore Engineering Corporation，Tianjin 300280，China

With the increasing complexity of prospecting objectives，reverse time migration (ＲTM) has attracted more and more attention due to its outstanding imaging quality． ＲTM is based on two- way wave equation， so it can avoid the limits of angle in traditional one- way wave equation migration，image reverse branch， prism waves and multi- reflected wave precisely and obtain accurate dynamic information． However，the huge demands for storage and computation as well as low frequency noises restrict its wide application． The normalized cross- correlation ima- ging conditions based on wave field decomposition are derived from traditional cross- correlation imaging condition， and it can eliminate the low- frequency noises effectively and improve the imaging resolution． The practical proce- dure includes separating source and receiver wave field into one- way components respectively，and conducting cross- correlation imaging condition to the post- separated wave field． In this way，the resolution and precision of the imaging result will be promoted greatly．