The following results were obtained in the study of the rabbits with experimental anemia and the patients with hypoplastic anemia both treated with ultra-short waves in the Diencephalon. 1) In the rabbits with experimental anemia induced by the venesection of blood, the phenylhydrazine and benzol intoxication, the period of time for the recovery of anemia was shortened in the cases with the treatment of ultra-short waves faster than in the cases without treatment. 2) In the rabbits with anemia induced by the venesection of blood and the phenylhydrazine intoxication, the bone marrow function were accelerated by successive irradiations sooner than by a single irradiation. 3) In one of three Patients with hypoplastic anemia some effect from the treatment was observable.