In the normal persons, ^<35>S is excreted in urine amounting 91-99% of injected lipoic acid-^<35>S within 24 hours. After peritoneal injection of lipoic acid-^<35>S in mice, ^<35>S invaded rapidly into the tissues and disappeared rapidly. With seven eczematic patients, the excretion of ^<35>S was less than that with normal subjects and the excretion peak was seen with the latter but not with the former. Unkown 5 spots of ^<35>S were seen on paper chromatogram. It seems that some relationships exist between disturbance of lipoic acid metabolism and hepatic, renal and adrenal disfunction and disorder of serum protein and blood sugar.