A new aporphine alkaloid, 6-formyl-1,2,9,10-tetramethoxy-6a,7-dehydroaporphine (1), was isolated from the aerial parts of Aconitum carmichaelii along with two known isoquinoline alkaloids, glaucine (2) and norglaucine hydrochloride (3). The structure of 1 was determined by extensive spectroscopic methods, especially 2D NMR analyses.