The yields of inorganic phosphate and base released from 5’-dTMP irradiated by30 keV N+ ion beam were investigated. The fluence effects of these yields and theinfluence with 0.1 mol/L NaOH treatment on them were presented. It was shown thatthe alkali treatment would not only increase the yield of inorganic phosphate

butalso damage and then split base released from the irradiated 5’-dTMP. When theirradiated samples were treated with 0.1 mol/L NaOH immediately

the yield ofinorganic phosphate was increased by a factor of 1.7 and the concentration of basedecreased to half of that in the sample’s water solution. Furthermore

the yield ofinorganic phosphate would increase by a factor of 2.8 after 40 min of alkalitreatment. Irradiation effects of ion beam were mainly direct ones and had a highervalue of G（Pi）

greater than 0.44 molecule/100eV.