An objective of the present invention is to provide a method for producing a nepodin-containing extract containing a high concentration of nepodin with less contaminants present therein thereby being able to be readily carried out on an industrial scale, when compared to the conventional techniques. The objective is solved by A method for producing a nepodin-containing Rumex plant extract, the method comprising the following steps (1) to (5): (1) a step of subjecting a Rumex plant to an extraction treatment using a nepodin-dissolving solvent to obtain a crude Rumex plant extract； (2) a step of subjecting the crude Rumex plant extract to a water-adding treatment and/or concentration treatment to obtain a solid crude Rumex plant extract； (3) a step of subjecting the solid crude Rumex plant extract to a weak alkali treatment to obtain a weak alkali insoluble product； (4) a step of subjecting the weak alkali insoluble product to a strong alkali treatment to obtain a strong alkali soluble product； and (5) a step of subjecting the strong alkali soluble product to a neutralization treatment to obtain the nepodin-containing Rumex plant extract.
