Abstract: AIM: To look for new principles of high activity and low toxicity from the flowers of Aconitum kusnezoffii Reichb. METHODS: Various chramatographic techniques were used to separate and purify the constituents. Their physical and chemical properties and spectral data were measured for structure elucidation. RESULTS: Seven compounds were isolated from the benzene extract of the flowers of Aconitum kusnezoffii Reichb, a medicinal plant of Ranunculaceae family. On the basis of spectral data (IR, MS, ¹HNMR ,¹³CNMR and DEPT) and comparisons with known compounds, their structures were identified as hypaconitine (I), 3-acetylaconitine (II), 3-acetylmesaconitine (III), 3-acetylaconifine (IV), mesaconitine (V), beiwutine (VI) and lepenine (VII). CONCLUSION: Compounds III and IV were new natural products. Compounds II～IV showed analgesic and antiinflammatory activities.