Seven compounds were isolated from the stem of Acanthopanax senticosus by repeated column chromatography. Their structures were elucidated as isovanillin (1), (-)-sesamin (2), isofraxidin (3), (+)-syringaresinol (4), 5-hydroxymethylfurfural (5), eleutheroside B (6), and eleutheroside E (7) by spectral analysis. Among them, isovanillin (1) was isolated for the first time from the family Araliaceae.