The yields of inorganic phosphate and base released from 5'-dTMP irradiated by 30 keV N + ion beam were investigated. The fluence effects of these yields and the influence with 0. 1 mol/L NaOH treatment on them were presented. It was shown that the alkali treatment would not only increase the yield of inorganic phosphate, but also damage and then split base released from the irradiated 5'-dTMP. When the irradiated samples were treated with 0. 1 mol/L NaOH immediately, the yield of inorganic phosphate was increased by a factor of 1. 7 and the concentration of base decreased to half of that in the sample's water solution. Furthermore, the yield of inorganic phosphate would increase by a factor of 2. 8 after 40 min of alkali treatment. Irradiation effects of ion beam were mainly direct ones and had a higher value of G (P i ), greater than 0. 44 molecule/100eV.
