In order to persuit the iron metabolism in Banti's disease, distribution and fractionation of the radioactive iron (Fe(59)) and non-radioactive iron in the red cells, serum and various organs such as liver or spleen were investigated by intravenous and oral administration of Fe(59) to the rabbits given serum or extract of the spleen of the patients with Banti's disease and the rabbits sympathectomized of the splenic branch. Following results were obtained. 1) On the intravenous administration of Fe(59) to the rabbits given patient serum of Banti's disease, the radioactive and non-radioactive iron tended to show increased distibution in the liver and spleen. It is clear from this finding that preservation of the iron in these organs is taken place. 2) In the rabbits given extracts of the spleen of the patients with Banti's disease, there are differences of the iron distribution between intravenous and oral administration of Fe(59); in the former almost the same results as in the serum administration was observed, while in the latter it is shown no remarkable changes in the organ distribution or rather somewhat decreasing tendency. These findings are suggestive of a possibility of the absorption disturbance of the iron in the gastrointestinal tract. 3) On the intravenous administration of Fe(59) to the rabbits sympathectomized of the splenic branch, the labeled isotope tended to show increasing in the liver and spleen as seen in the serum administrating animals. This finding apparently indicated that preservation of the iron to the organs is occurred. 4) It is reasonable to presume from above findings that the preservation of iron to the organs such as liver or spleen plays an important role for anemia and iron deficiency condition of the erythroblasts in Banti's disease and also it is suggested that a possibility of disturbance of iron absorption could be existed in the gastrintestinal tract.