In view of the fact that the disturbed thiamine metabolism by some types of eczema and dermatitis was often associated with macrocytic anemia, functional disturbance of the liver, and achylia gastrica, studies were carried out on these syndromes. Among 103 cases, mainly of dermatitis and eczema, 16 cases were shown to have macrocytic anemia and 9 cases normocytic anemia. Ten cases of macrocytic anemia, namely 62.5% of the 16 cases showed functional disturbance of the liver, while in 12 cases achylia gastrica was observed. Rabbits developed anemia in the advanced stage of thiamine deficiency, though the symptom was not manifested during the period when the deficiency was in progress. However it was supposed by the determination of mean corpuscular volume and mean corpuscular hemoglobin concentration that the erythrocytes had a tendency to be macrocytic in thiamine deficiency.