Abstract: The Flovonearabinoside,isolated from Kwang-Chi-sheng,has a transient depressor effect in anesthetized dogs. On repeated injections,tachyphylaxis was noted.From our experiments the glycoside showed a powerful diuretic action.The urine volume was increased when intravenously injected at doses of 0.5—2mg/kg on 21 anesthetized dogs. The substance was given orally and subcutaneously to 232 unancsthetized rats at a dose of 34 mg/kg,the urine volume increased 16 and 23% respectively,and 27% increased was recorded at a dose of 100 mg/kg intraperitonealy as compared with the controls.The diuretic action of the arabinoside was compared with aminophylline,the potency of the former was found to be about 4/5 to 3/5 of the latter at same doses on rats. When the drug was injected intraperitonealy,the LD₅₀for mice was found to be 1173mg/kg,which is about one fourth that of aminophylline,In case of intoxication,clonic-tonic convulsions occurred after 10—20 minutes of the injection,and death was due to respiratory failure.