With the purpose to study the effect of chlorpromazine on body fluids in vivo, especially the changes in the amounts of pyruvate and α-ketoglutaric acid in ventricle fluid, spinal fluid of lumbar region and blood, the author estimated according to Shimazono-Shimizu method the amounts of pyruvate and α-ketoglutaric acid in blood and spinal fluids obtained from schizophrenic patients at rest or after adminstration of the optimum dosage of chlorpromazine (C. P.) or iaomytal (Iso) and given lobotomy. The results are as follows: 1. No marked difference between the amount of pyruvate or α-ketoglutaraic acid in the venous blood obtained from the persons at rest with empty stomach and the same obtained after the administration of 200 mg C. P for 10 days or intramascular injection of 50 mg C. P. 2. In the estimation of two acid amounts in ventricle fluid, spinal fluid of lumbar regions and elbow venous blood obtained at about the same time after intramascular injection of 100 mg C. P, it has been found to be in the order of the amount of pyruvate in blood > the same in ventricle fluid > that in spinal fluid of lumbar region. The amount of α-ketoglutaric acid proves to be in the order of that in ventricle fluid > that in blood > that in spinal fluid of lumbar region. Each of these values shows a slightly decreasing tendency as compared with those in the control to which no drug has been administered. 3. After the intravenous administration of 0.5 g Isomytal (Iso) the amounts of both acids distributed at various sites have been estimated in the same manner as above. In this instance the amounts of pyruvate and α-ketoglutaric acid distributed at different sites show about the same tendency as observed in the control as well as in the cases given C. P. However, when these values are compared with those given C, P. and those at each site, the values of both acids in blood and in spinal fluid at lumbar region show a decreasing teudency as compared with the control, but in ventricle fluid the amount of α-ketoglutaric acid is slightly increased. In other words, it appears that the changes in the amount of α-ketoglutaric acid in cerbral fluid behave differently from those in the case given C. P. Moreover, this phenomenon seems to be due to the difference in the mechanism of C. P. and Iso. acting on the brain.