Abstract: Direct Current Current Voltage(DCIV) technique has been applied to study the Si-film/SiO₂ interface quality of Partially Depleted SOI that were fabricated on a SMART-CUT wafer. the samples were exposed to Co-60 gamma rays irradiation to monitor the development of PDSOI back-channel interface states. The paper gives the integrated measurement mechanism, experiment flow and result analysis, then it can not only obtain the back-channel interface trap density and its equivalent energy level, but also can calculate the u-shape map (mainly in near the center of the silicon forbidden zone) of the interfacial trap energy density with the change of energy level in the silicon forbidden zone, which provides reference for the enhancing of PDSOI devices.