By chromatography on a column of cellulose, from the combined alkaloids obtained by the ether treatment of the roots with rhizomes of Veratrum lobelianum Bernh., two alkaloids (I with Rf 0.10 and II with Rf 0.82) were isolated. Alkaloid (I) C37H59O12N had mp 202-204°C, [α]~ -18.7° (c 0.95; pyridine). Through alkaline hydrolysis, paper chromatography with markers, UV spectrum of its sulfuric-acid solution, and comparison with methanolysis products of deacetylprotoveratrine A (III) (mixture showed no melting point depression), it was concluded to be 3-(d-2-hydroxy-2-methylbutyryl)-15-(l-2'-methylbutyryl)protoverine, named dideacetylprotoveratrine A. It is the first time found in Veratrum genus and confirmed as a native ester alkaloid by investigating stability under alkaloid preparation conditions. Alkaloid (II) C14H33O14 had mp 228-229°C, [α]~ -70° (c 0.38; pyridine). Alkaline hydrolysis, paper chromatography with markers, UV spectrum, and comparison with germitetrine sample (mixture showed no melting point depression) confirmed it as germitetrine.