Three new diterpene alkaloids, 16,17-dihydro-12β,16β-epoxynapelline (1), N-deethyl-N-methyl-12-epi-napelline (2) and 11-epi-16α, 17-dihydroxylepenine (3), along with twenty-six known alkaloids (4-29) were isolated from the roots of Aconitum nagarum var. lasiandrum. The chemical structures of the new compounds were established by HR-MS as well as 1D- and 2D-NMR spectroscopic analysis. The absolute stereochemistry of 1 was confirmed by X-ray crystallography.