The following results were drawn from the experiment conducted to see the effect of ginseng alcohol extract on the mitochondrial oxidation of the rat liver. 1) Mitochondrial oxygen consumption increased in the low concentration and decreased in the high concentration of ginseng alcohol extract. 2) When the mitochondria was destroyed mechanically or was swollen by low concentration of AgNO₃, mitochondrial oxygen consumption was inhibited in all concentration of ginseng alcohol extract. 3) Oxygen consumption of intact mitochondria increased in the low concentration but decreased in the high concentration of sodium deoxycholate. 4) Ginseng alcohol extract inhibited cytochrome oxidase activities of liver mitochondria. These results suggest that low concentration of ginseng alcohol extract activates the oxygen consumption of liver mitochondria by increasing the permeability of the mitochondrial membrane and high concentration of the extract inhibit the oxygen consumption by inhibiting the enzyme activity related to respiration.