A phthalide, levistolide A (1), and six coumarins, demethylsuberosin (2), fraxetin (3), (-)-marmesinin (4), 3'(S)-O-P-D-glucopyranosyl-3',4'-dihydroxanthyletin (5), 3'(R)-O-P-D-glucopyranosyl-3',4'-dihydroxanthyletin (6), and isopraeroside IV (7) were isolated from the methanolic extract of the roots of Angelica tenuissima Nakai. Their chemical structures were confirmed by comparing spectroscopic and reported data. All seven compounds were isolated for the first time from this plant source. The anti-allergic activities of compounds 1-7 were examined using human mast cells, and compounds 1-3 at 10 liM potently suppressed IL-6 expression and inhibited histamine release from human mast cells by more than 30%.