The components of the herbs of Aconitum carmichaeli were studied by HPLC coupled with ESI-MS~n.Extracted ion chromatograms was applied to detect low level compounds.Forty eight compounds were identified comparing on retention time,m/z and MS~n data.There were eight diester-diterpenoid alka- loids,seven monoester-diterpenoid alkaloids and twenty nine lipo-alkaloids.The relative abundance of diester-diterpenoid alkaloids were more than those of monoester-diterpenoid alkaloids and lipo-alkaioids in the herbs o...