Abstract: The effect of decoctum of Fu-Tze on the blood vessels had been studied. Blood pressure of anaesthetized animal had a rapid,short-durationed drop without significant change of heart function.This depression could be eliminated or blocked by atropine and benadryl.With modified Khayutin's apparatus it has been shown that decoctum has a significant, direct vasodilatation on the blood vessel of muscle of hind limb, probably owing to the muscaline-like or histamine-like substences it contains. With the Caverina's method a coronal vasodilatation, indenpedent of blood pressure and heart rate, has also been observed.