Abstract: This paper investigates the total radiation dose effects on 4 pieces of military power MOSFET 2N7266 under 60Co γ-radiation. During the γ-radiation, the time history of the DUT’s electrical characteristics along with the total radiation dose(TID) is obtained by using JT-1 transistor plotter and computer controlled vidicon. The DUT’s threshold voltage, breakdown voltage and leakage current characteristics are shown in tables and curves against the total radiation dose, from which the total radiation dose resistant capacity can be found for each individual device. The results may provide a reference for applications of 2N7266 MOSFET device in future engineering designs.