The　measurement　of　clustered　damages　in　Pt-chemotherapeutic-drugs-DNA　complexes　induced　by　low-energy　(0-30　eV)　electrons　(LEEs)　may　provide　further　understanding　of　the　synergy　mechanism　in　cancer　treatment　with　concomitant　chemoradiation　therapy　(CRT).　Five-monolayer　films　of　Pt-DNA　complexes,　containing　cisplatin,　carboplatin　and　oxaliplatin　with　ratio　5:1　were　irradiated　with　mono-energetic　electrons　of　10　eV,　the　most　prominent　energy　for　bond　dissociation　by　LEE　impact.　Damages　to　plasmid　DNA　including　crosslinks,　SSBs,　DSBs　and　the　loss　of　the　supercoiled　configuration　were　analyzed　by　the　electrophoresis.　Base　damages　(BDs)　occurring　within　two　turns　of　DNA　helix　were　detected　by　the　treatment　of　E.　coli　base　excision　repair　endonuclease　(Nth　and　Fpg).　The　total　DNA　damages　to　Pt-DNA　complexes　was　found　to　be　350　+/-　42,　296　+/-　45　and　434　+/-　46　x10(-15)　electron(-1)molecule(-1),　respectively,　while　the　percentages　of　BDs　in　this　total　were　56%,　54%　and　60%,　respectively.　Compared　to　unmodified　DNA,　binding　of　Pt-drugs　to　DNA　increased　BDs　by　factors　of　1.9,　1.6　and　2.6,　respectively,　which　partly　resulted　in　significant　enhancements　of　potentially　lethal　lesions　(i.　e.,　crosslinks,　double　strand　breaks　(DSBs)　and　non-DSB　cluster　damages).　These　results　reveal　the　significant　role　that　LEEs　play　in　the　formation　of　clustered　DNA　damages　related　to　BDs,　which　are　expected　to　contribute　to　the　higher　efficacy　of　cancer　treatment　by　CRT　with　the　Pt-drugs　investigated.