Öz Due to the recent progress achieved in the seıamic data acguistion and digital processing teehni- ques, the ability of the exploration seîsmologist to detect many important objeetives is widely enhanced. One cf these objeetives is to detect overpressured zones. This deteetion is very impor­ tant for the petrolcüm geologist and the drilling engineer for security and drilling arrangement purposes. The present paper explains this phenomena and reviews the laboratory experimental re- sults, and the required field seismic measurements carried out. Consequently many conciusions are established.