PURPOSE: To obtain shikonin having high purity and useful as a raw material for pharmacenticals, etc., in high yield by adding an alkaline aqueous solution to an extract of shikonin ester extracted with an organic solvent, hydrolyzing the ester without separating the aqueous phase from the organic phase and separating the objective compound from the aqueous phase.

CONSTITUTION: Natural SHIKON (root of Lithospermum erythrorhizon) or callus of Lithospermum erythrorhizon prepared by tissue culture is extracted by using an organic solvent as an extraction solvent. The extract liquid containing a shikonin ester of formula (R is alkyl) is added with an alkaline aqueous solution such as aqueous solution of potassium hydroxide, sodium hydroxide, etc., and the ester is hydrolyzed in the presence of the extraction solvent without separating the aqueous phase from the organic phase. After the hydrolysis, the aqueous phase is separated from the mixture and shikonin is separated from the aqueous phase to obtain shikonin having bactericidal action, exhibiting excellent effect against various dermatic diseases and useful also as a dye, etc. The compound can be produced in high purity and efficiency while suppressing the formation of hydrolysis by-product.