Melanogenesis-inhibitory constituents ofLigusticum sinenseare provided. The melanogenesis-inhibitory constituents can be compound I, II, or III having the chemical structures as follow, respectively.提供一種具有藁本中抑制黑色素生成之成分。此藁本成分例如可為化合物I、II或III,其中化合物I、II、III具有如下之化學結構式。