Abstract: This paper suggests a new mapping technique implemented on PC-1500. The method make improvement in three respects: (1 ) use curvilinear velocity models instead of linear ones. (2) replace arcing method with ray-tracing for spatial correction, (3) directly implement migration process on PC-1500 instead of using migration tables. As a result, the migration and mapping jobs become more accurate and easy. Some problems associated with the new technique are studied with several applied examples.