The alkaloidal constituents of the roots and aerial parts of Aconitum sanyoense NAKAI var. tonense NAKAI collected at Kuzure-sawa (Nagano prefecture) were reinvestigated. From the aerial parts, two new C19-diterpene alkaloids, 10-hydroxyisotalatizidine (5) and 10-hydroxytalatizamine (7), were isolated along with five known diterpene alkaloids and two aporphine alkaloids. Three new alkaloids, i.e. 10-hydroxyisotalatizidine (5), 1,15-di-O-acetylhypognavine (11), and 1-0-acetylhypognavine (12), were obtained from the roots in addition to eight known diterpene alkaloids. The structure of Hanamiyama base (14), found in the previous examination of this plant, was determined to be deacetylhanamisine.