New ester derivatives of alkoxybenzoyldeoxyfluorouridine of the general formula ##STR1## wherein R stands for an alkoxy group having 1 to 4 carbon atoms, m for 1 or 2, and n for 3 or 4 with the proviso that when m is 2, the adjacent two R's may be combined to form an alkylenedioxy group as a whole. These derivatives are prepared by acylating a 2'-deoxy-3',5'-di-O-alkylcarbonyl-5-fluorouridine with corresponding benzoyl halides and are useful as active ingredients for anti-tumor agents, especially for oral administration.