In order to find the cardiotonic constituents of lateral roots of Aconitum carmichaelii Debx., the investigation was carried out. Silica gel column chromatography, Sephadex LH-20, medium-pressure MCI and reverse phase ODS column chromatography were used to separate the 90% EtOH extract of the lateral roots of Aconitum carmichaelii Debx. The structures of the isolated compounds have been identified by chemical properties and spectroscopic analyses. Ten compounds were isolated and their structures were elucidated as benzoic acid-5-hydroxy-2-benzoyl-amino methyl ester (1), honokiol (2), pinoresinol (3), salicylic acid (4), p-hydroxy-cinnamic acid (5), songorine (6), karakoline (7), mesaconitine (8), hypaconitine (9) and 14-benzoylhypaconitine (10), separetely. Compound 1 is a new compound and its structure has been established by NMR, HR-ESI-MS, UV, IR and X-Ray. Compound 2-5 are isolated from the lateral roots of Aconitum carmichaelii Debx. for the first time.