Disclosed is a process for producing a 10-hydroxyanthracycline of the following formula (II) which comprises reacting a compound of the following formula (I) or an acid addition salt thereof with an N-oxide of a tertiary amine ##STR1## wherein: R.sup.1 through R.sup.6 each designate any of H, OH and OCH.sub.3 ; R.sup.7 designates any of H, OH and a sugar residue; and R.sup.8 designates any of C.sub.2 H.sub.5, COCH.sub.3, CH(OH)CH.sub.3, CH(OH)CH.sub.2 (OH) and COCH.sub.2 OH. In accordance with this process, it is possible to efficiently introduce a hydroxyl group into the 10-position of an anthracycline having no substitutent at the same position thereof.