From the root of Angelica gigas $N_{AKAI}$ (Umbelliferae), known as "Tang Gui" in Korea, substance A (colorless needle crystal, $C_{14}H_{14}O_{4}$, m.p. $178^{circ}$) and B (white plate crystal, $C_{19}H_{20}O_{5}$, m.p. $111^{circ}$) were obtained. Acetylation of "A" gave its monoacetate, white needles, $C_{16}H_{16}O_{5}$. Saponification of "B" with 5% sodium hydroxide produced "A" and senecionic acid. Examination using I.R. and N.M.R. spectra shows that "A" is identical with decursinol and that "B" with decursin. The root also appears to contain five coumarin derivatives and two steroidal compounds.