This study is about the seismic reflection structural interpretation of the Fatha Formation in Tertiary and Shiranish and Nahr Umr Formations in Cretaceous of Wasit structure , the 3D seismic data volume have been used in the interpretation process based on synthetic traces ,the tops of the three Reflectors s were determined and picked using an interpretation using specialized computer program . After these formations have been traced overall the area the subsurface structural image can be extracted in order to determined were hydrocarbons could possibly exist , Nahr Umr is expected to be a hydrocarbon reservoir in this research .