The changes in electrical properties of cement pastes incorporating CNT and CF exposed to various deterioration factors were examined in this study. The electrical resistivity changes of the paste samples were measured via the two-probe method. In addition, microstructure changes of the samples before and after exposure to deterioration factors were investigated using various analytical methods. In the samples exposed to the various deterioration conditions, the electrical resistivity increased with exposure time, and a rapid change in the electrical resistivity due to the polarization effect was also observed. However, it can be found that the incorporation of micro-sized CF can mitigate the increase in the electrical resistivity of the samples resulting from the deterioration, improving their electrical stability upon exposure to various environments. Exposure to the deterioration conditions of the samples caused changes in their physicochemical structures, which resulted in changes in their electrical resistivity.