When hemoglobin of the normal mouse was studied as a control to observe the changes in hemoglobin of Rauscher Leukemia, the absorption curve of hemolysate was drawn and an OxyHb type of absorption curve was observed. In alkali denaturation test the existence of two or more components was suggested. By means of starch-gel electrophoresis of hemolysate five components were observed in early fetus and four components in late fetus, newborn and adult mice and then their component ratios were calculated. By column chromatography of hemolysate the exisitence of four components was certified and by Betke's staining Betke positive erythrocytes were found numerous in late fetus and newborn mice and they decreased rapidly in number afterwards.