PURPOSE:To raise yield of dyestuff of safflower and to enable industrial mass production of dyestuff of safflower, by cultivating callus of safflower in a liquid medium, from which a specific ion is removed, containing an aromatic amino acid of D form or DL form. CONSTITUTION:A cell group of safflower is cultivated in a liquid medium, from which ammonium ion and/or calcium ion and/or magnesium ion is removed, containing an aromatic amino acid of D form or DL form. Yield of dyestuff of safflower can be raised by adding a coloring promoter substance to the liquid medium prepared as mentioned above. One or more selected from cellulose powder, fine crystal cellulose, filter paper, chitin, cotton and silk are used as the coloring promoting substance.
