Abstract: Two alkaloids have been isolated from the chinese drug, Huang-tsao-wu (Aconitum vilmorrianum), and provisionally named as vilmorrianine A and B respectively. The vilmorrianine A, C₃₃H₄₇O₉N, m.p.182-184℃ was found to be a monoester base with two hydroxy, four methoxy and N-ethyl groups. When the alkaloid was hydrolysed in alcoholic potash solution, an anisic acid and syrup amino alcohol were obtained. The latter compound formed crystalline acetate with melting point 205-207℃. The extended formula of vilmorrianine A may be expressed as C₁₉H₂₁(OCH₃)₄ (OH)₂ (CH₃OC₆H₄COO) (NC₂H₅). The vilmorrianine B has the emperical formula, C₂₁H₃₃O₄N, m.p. 184-185℃, and its crystalline perchlorate m.p. 138-140℃. On account of the small quantity in hand, its was not further studied.