The purpose of this study is to develop a mass preparation method of (+)-decursinol from Angelica gigas roots. Recently; it has been shown that (+)-decursin, (+)-decursinol angelate and its analogues, isolated from Angelica gigas roots, exhibit various biological activities such as antitumor, antibacterial and neuroprotective activities. The contents of these compounds, ester form of (+)-decursinol, is very high in the Angelica gigas roots, whereas the content of (+)-decursinol itself is very low Therefore, (+)-decursinol which can be used as starting material to synthesize various its analogues was easily prepared from decursin analogues in the Angelica gigas roots. In order to achieve such aim, the Ether-Fr. of the ethanol exact of Angelica gigas roots was hydrolysed with various alkalis and solvents. As a result, the order of (+)-decursinol preparation was 1) NaOH, KOH, 2) $K_2CO_3$, and 3) $NaHCO_3$ as alkali. Also, the yield of (+)-decursinol was higher in diethyl ether than any other solvent conditions. From 1 kg of dried Angelica gigas roots, we could obtain 27.4 g of (+)-decursinol as a pure white solid.