A process for preparing the 9-amino camptothecin of formula (I); said process comprising: (1) reacting a compound of formula (III), wherein the hydroxy group on ring A is in the 10- or 12-position, with a nitrating agent, so obtaining a corresponding compound of formula (IV); (2) converting the compound of formula (IV) into a corresponding compound of formula (V), wherein XO is a group that can be removed reductively; and (3) reductively removing the said XO group and reducing the nitro group of the compound of formula (V), so obtaining the 9-amino camptothecin of formula (I), a known antitumor compound. The present invention includes also in its scope compounds having the above reported formula (V) and compound of formula (VII), which are endowed with antitumor activity