Senescence is one of the fundamentals of cellular vital motion, which is usually a gradual and intricate process of cellular physiologic and biochemical reaction. Cellular senescence is closely related to the morphic, structure and functions of the mitochondrion. In this process, mitochondrion has many changes in biology, physiology and moleculeology. Mitochondrion generates free radical which damages itself and gradually promotes itself senescence. MtD-NA mutation also promotes itself senescence.