The total ionizing dose (TID) effect of Nb∶SrTiO3 resistive switching cells and 1T1R structures were investigated by using X-rays. The experimental results show that the Nb∶SrTiO3 cells exhibit superior radiation tolerance exceeding 10 Mrad(Si) after which the resistive switching properties sustain well and the resistance states do not flip. However, the 1T1R structure is much more susceptible to ionizing radiation due to the performance degradation of NMOS access transistor. The radiation-induced positive oxide-trapped charges can result in the negative threshold shift and increase the leakage current of NMOS transistors, which leads to the unexpected read/write operation of the Nb∶SrTiO3 cell at “off” state(VG=0 V). Therefore, the radiation tolerance of 1T1R structure can be improved significantly by using hardened NMOS transistors.