Huang-tsao-wu (Aconitum vilmorrianum Kom,) is an important herb drug popular in Yunnan,Three alkaloids,vilmorrianine A,B and a minor component,had boen isolated proviously from its roots by Zhu Yuan-lung and Zhu Ruan-hung,but their structures wore not determined,In this paper we roported the chomical studies of the three diterpenoid estor alkaloids of aconitine-type isolated from this plant,One is identical with vilmorrianine A,and the other one,named vilmorrianine C,is probably the same substance as the minor alkaloid of Zhu Yuan-luang et al.The chemical structures of vilmorrianine A and C have been determined to be 2 and 3 respectively by spectroscopic analyses (IR,UV,NMR,MS) and chemical studies,Vlmorrianine B was found to be identical with yunaconitine (1) recently reported by Cheng Si-ying.