Abstract:From the root of Aconitum pseudogeniculatum W. T. Wang, collected from the west of Sichuan province, six diterpenoid alkaloids were isolated and identified as denudatine ( Ⅰ ), chasmanine ( Ⅱ ), talatisamine (Ⅲ), yunaconitine (Ⅳ), crassicauline Ⅰ (Ⅴ) and vilmorrinianine C (Ⅵ). Yunaconitine, the major alkaloid of the plant, and its chemically transformed products pseudaconine and tetraacetylpseudaconine, showed antiinflammatory activities.