Purpose: To determine new metabolites of the main components of Angelica gigas known to give anti-inflammation and pain relief Methods: Decursinol and blank sample were metabolized in human liver microsomes. The metabolized samples were centrifuged and deproteinated by adding 3 mL acetonitrile. The acetonitrile layer was concentrated and reconstituted in methanol. Finally, the prepared sample was injected into the LC-Q- TOF-MS. Results: Four new metabolites of decursinol with m/z ranging from 263.0912 ~ 263.0920 were identified as hydroxylated forms of decursinol, and the hydroxylated position of each metabolite was characterized using TOF mass spectrum. Their error values of detected m/z were 0.38 ~ 2.29 ppm, which indicates high accuracy of analysis. Conclusion: Previously unreported decursinol metabolites have been identified in this study. The findings provide athe basis for further pharmaceutical studies and functional food development using decursinol.