The influence of radiation on the thermodynamic properties of liquid systems that are governed by the radiation-induced change in the chemical potentials of the liquid and its components has been studied. The irradiation of coexisting phases in the stationary state is shown to result in a shift of the phase transition point parameters. The temperature shift of the first-order phase transition under the influence of radiation is evaluated with regard to both the entropy and interaction factors in the chemical potential of the system. The results obtained from the MD simulation of the radiation influence on 10% saline quantitatively confirm the predictions of the introduced theoretical model of the irradiation process. To verify our theoretical assumptions concerning modifications in the local structure of the examined saline (water solution of NaCl at 10% concentration), experiments under the influence of irradiation were done.