The biologic sonar discovered in the odontocetes,especially in dolphins which are better developed,play important roles in their daily activities including predation,communication and recognition etc.For decades,artificial sonar produced by simulating the function of the biological sonar has got well development and been widely used in peoples nautical activities.However,in some performance,biological sonar has distinct advantages.Numerous studies indicate that the sonar of dolphin has unique features including high stabilization and accuracy,broad frequency band and strong recognition capability etc.Nowadays,the study on vocal mechanism of biologic sonar and manufacture of bionic equipment attract peoples attention.Actually,the function and characteristics of biological sonar in the odontocetes are analogical and we have dissected four species of odontocetes(pygmy sperm whale,cowfish,Chinese white dolphin and beaked whale).We can clearly identify the phonic lips and air sacs in their heads which play important roles in biologic sonar after dissecting and analyzing structure of their heads.The four species were submitted to CT scans to gain sectional image data and the three-dimensional models of skulls,breathing tubes and air sacs were reconstructed.We analyzed structures of phonic tissues and finished mechanical performance testing which helped us screen out compatible bionic materials.Combining the data above,a hypothesis of phonic mechanism which was derived from dolphins sound source was put forward and the simple model equipment was designed.During the test experiment,we had a further understanding on the sonar of dolphin and accumulated wealth for later research.