PAS glycosuria was investigated. And the results were as follows. 1. In the patitents with the administion of PAS, the value of glucuronic acid was generally increased in blood and urine, and it's blood value was 8.8mg/dl on the average and it's excretive dosis into urine was 549mg. The Nylander's reaction showed a weak or strong positive in 2 of 17 cases urine. 2. The glucose level in blood and the glucuronic acid level in urine were measured in each fasting and after-meal condition, and the correlation between each of them and Nylander's reaction was investigated. The correlation between the glucose level in blood and the Nylander's reaction was not observed, but the correlation between the glucuronic acid level in urine and the Nylander's reacton was observed. 3. On the esperimental administration of PAS, the excretive dosis of glucuronic acid into urine showed the highest level after 90 or 120 minutes of the administration, in non-hepatic disease or health, and came down to the level, which was shown before the administration, after 4 hours of the administration, but it showed the highest level after 3 or 4 hours of the administration in liver disease. Therefore, it was supposed that PAS was combined with glucuronic acid and excreted into urine and this combination had a connection with liver function. 4. Since the results that glucuronic acid was separated from the PAS-glycosuria which was experimentally provoked on rabbit and was qualitatively tested, it was supposed that there was the compound of glucuronic acid and PAS and the combination was an esterfrorm. On the examination of the separated solution by the paper chromatography, the existence of glucose was denied and the separation between PAS and glucuronic acid could be obtained after the hydrolysis. The absorption curve of the separated solution displayed the absorption maxima at 269 and 390mμ and, after it,s hydrolysis, it showed the absorption curve, with the absorption maximum at 270mμ, which agreed with the absorption curve of PAS. The absorption curve of O-aminophenol glucuronide, as a control, displayed the absorption maxima at 270 and 285mμ and, after it's hydrolysis, it showed the absorption curve, with the absorption maximum at 285mμ, which agreed with the absorption curve of O-aminophenol. 5. Therefore, it was concluded that the genesis of PAS-glycosuria was a combined glucuronic acid with PAS.