The data presented in the second paper indicated that in Patients with gastric cancer the preoperative determinations of albumin content and albuminglobulin ratio were of value for judging the patient's condition of nutrition and operative prognosis, but that the alternation occurring in the concentrations of plasma protein fractions following operation was not always proportional to the preoperative degree of protein deficiency and the clinical picture. Therefore this paper is concerned with the study on hypoproteinemia in patients with gastric cancer on the base of the examination of both the concentration and the total circulating mass of plasma protein. Blood volume, plasma volume, cell volume, total circulating plasma protein mass, total circulating hemoglobin mass, plasma protein contration and hemoglobin concentration in 14 patients with gastric cancer were measured before and after operation. As control material similar studies were made in 11 normal persons, in 13 patients with gastroduodenal ulcer, in 5 cases of cancer of the brest and in 4 cases of Graves' disease. Additional studies were done to determine a standard of blood requirement to be transfused by investigating the effect of transion in the cases in which blnod had been administered before and after operation. The resnlts of these studies were as follows: 1. In patients with gastric cancer there was a decrease in blood volume and in cell volume. 2. Plasma volume was above normal in many patients with gastric cancer and decreased in only a few cases. 3. The decreased blood volume in patients with gastric cancer chiefly was due to a reduction of cell volume, and there were a few cases where plasma volume was concerned in it. 4. The prognosis of the patients with gastric cancer who had a decreased blood volume was poor. 5. In patients with gastric cancer a decrease of both total circulating hemoglobin mass was noted, the loss of the later being more pronounced. 6. In patients with gastric cancer the transfusion of at least 1000 cc each of whole blood and plasma was considered necessary before operation. 7. In patients with gastric cancer blood volume, plasma volune and cell volume were reduced 4 to 8 days after the resection of the stomach. After the 12th postoperative day, plasma volume increased, whereas cell volume did little. 8. Total circulating plasma protein mass in patients with gastric cancer decreased 4 to 8 days after operation, but increased after the 12th postoperative day. 9. Total circulating hemoglobin mass in patientients with gastric cancer.was markedly decreased following resection of the stomach. The value showed a especially sharp decrease on the 4th postoperative day and still further decreased gradually afterwards and there were a few cases in which it shifted to the increase on discharge from the hospital. 10. There were the cases of gastric cancer where a discrepancy between the concentration and the total circulating mass of blasma protein was noted and this tendency was more striking in both of hemoglobin. It was often difficult, therefore, to estimate total circulating mass of plasma protein and hemoglobin by the determination of only concentration of plasma protein and hemoglobin. 11. Total plasma protein mass rather than total total hemoglbin mass was suitable as an index of tissue protein deficiency in the postoperative course of patients with gastric cancer. 12. The variations in values of blood determined after operation in patiens with gastric cancer depended on the preoperative state of body nutrition and on the amount of blood postoperatively transfused. In well nourished patients and in those transfused over 800cc of blood, the degree of reduction in blood volume aud plasma volume was low, and on discharge from the hospital, there was a tendency for total circulating plasma protein mass to increase above the preoperative value.