ABSTRACT
Mitochondria is an important organelle in mammalian cells with multiple functions,such as ener-gy production and cell homeostasis maintaining. It is known that hundreds of diseases are associated with mi-tochondrial defects. The studies show that the exoge-nous mitochondria can directly enter mammalian cells in vitro, and they also can quickly transform into ani-mal tissues by local or intravenous injection. Current-ly, it has raised a new therapeutic strategy for mito-chondrial diseases, called mitotherapy, which trans-plants exogenous functional mitochondria into mito-chondria-defective cells. The mitochondria in recipient cells play their own roles, including energy produc-tion,maintaining free radical balance,and cell viabili-ty recovery. Since there is no effective method for mito-chondria-related diseases up to now, the mitotherapy will provide a new approach for the prevention and treatment of these diseases.