In the previous commuication, one of us (Chu) reported the isolation of a new alkaloid from the leaves and stems of Chinese Aconitum.A.delavayi Franch.Its local anaesthetic action is found to be twice as much as that of cocaine.This paper describes the isolation of a second new one from the root of another aconitum spp.collected from the same region; its empirical formula is the same as that of aconitine, but differs in melting point and other properties, so that the name isoaconitine is provisionally assigned.