The application of ultrasound to biotechnology is one of the new interesting research fields. A number of studies has shown that some biochemical processes can be activated by ultrasound in the presence of enzymes and cells. Generally,lower intensity ultrasound can increase the activity of enzymes and immobilised enzymes or improve the metabolism of cells by the improvement of mechanism of mass-transfer of substrates.The advance and future of applications of ultrasound to biotechnology is discussed by some examples given.