Application of low intensity ultrasonic waves to the biotechnology is one of new and hot research fields. The physical mechanisms of ultrasound mainly include the effects of mass transfer ,heating and cavitation. Many researchers found that low intensity ultrasonic waves could accelerate the interacton of substrate and help reactant to enter the active center of enzyme and production to leave center; it could also alter the permeability of membrane and enhance the transfer of mass, and so promote the production of beneficial matter and the absorption of drug to cells; in addition ,it could raise the efficiency of cell metabolism and the growth of cells; so low intensity ultrasonic waves can be used in enzyme engineering, fermentation engineering, cell engineering and biological therapeutics of Neoplasm. In this paper, we reviewed the application of low intensity ultrasound to biotechnology at home and abroad.