Studies were made by observing the effect of continued X-ray irradiation of small and medium dosages, and one massive dosage at one time on whole rabbit's body which animals have been administered of ethanol, and subsequently studied the findings of the blood picture examination which included the numbers of red and white blood cells, hemoglobin content, and the numbers of erythrocytes containing Heinz bodies (after Yoshida et Kawamura's), the variation of toxic granules in leucocytes, and the histological changes of liver, spleen, kidney and bone marrow. The rabbits which have been irradiated with a single massive dosage were observed of reticulo-endothelial function and resistance of erythrocytes. 1. The blood picture of the rabbits which had daily irradiation for a period of 200 days with the dosage of 10 r(9.5 r/min.) whole body and fed with 5% ethanol 10 cc/kg daily was compared with the one of the control animals which had no ethanol. Results showed there were no change seen in numbers of erythrocytes and hemoglobin quantity but the number of leucocytic reduction, or the increase in the erythrocytes containing Heinz body and the leucocytes having toxic granules were found to be less than the controls. Histological findings of liver showed practically no difference between ethanol administered rabbits and the controls. Atrophy of follicles of spleen, deposition of hemosiderin, degeneration of nephritic tubules, lowering cellular content in bone marrow could be seen in both groups, but ethanol administered group showed less change than the controls. 2. The rabbits which had daily X-ray irradiation of 300 r (11.1 r/min.) for a period of 10 days or 300 r (17.6 r/min.) for a period of 4 days were given to the entire body of animals of 3 groups: each group was administered of 3.53% ethanol or beer (Asahi brand) 10 cc/kg during and after the time of irradiation, and they were contrasted with those groups which had no ethanol or beer. It was found that those animals fed with ethanol or beer did recover earlier from blood disturbance than those of the controls. While, the effect was less than control in the histological changes whether they had ethanol or beer among above three groups of animal. 3. The rabbits which had a single irradiation of 1000 r (120.5 r/min.) dosage at one time on the whole body and fed with 5% ethanol 10cc/kg showed somewhat less blood changes, and did recover earlier from blood disturbance than the controls. The function of reticuloendothelial system was reduced in both ethanol administered group or control animals for a while following the irradiation, but later, the controls returned to the condition closed to the pre-irradiation, while the ethanol group showed heightened condition of pre-irradiation time as well as milder histological changes than the controls.