Abstract: AIM: To look for new principles of high activity and low toxicity from the leaves of Aconitum kusnezoffii Reichb. METHODS: The constituents were separated by using various column chromatography and their sturctures were identified on the basis of spectral analysis. RESULTS: Three compounds were isolated from the leaves of Aconitum kusnezoffii. Their structures were elucidated as beiwutine (I). 8-OEt-14-benzoylmesaconine (II) and beiwucine (III). CONCLUSION: Compound III was shown to be a new diterpenoid alkaloid.