The temperature dependence of relative permittivity and conductivity of ex-vivo pig liver, lung and heart at 2 450 MHz was studied. The relative permittivity and conductivity of three kinds of biological tissues were measured by the open-end coaxial line method. The dielectric model was fitted according to the principle of least square method. The results showed that the relative permittivity and conductivity of pig liver, pig lung and pig heart decreased with the increase of tissue temperature from 20 to 80 ℃. The relative permittivity and conductivity models of pig liver, pig lung and pig heart were established to reflect the law of dielectric properties of biological tissue changing with temperature and provide a reference for the parameters setting of thermal ablation temperature field.
