Electrical conduction characteristics in polyetherimide (PEI) have been investigated at electric fields of 0.9–27 MV/m over temperatures of 50–100 °C. It is found that the current density of PEI increases with the increase of electric field and temperature and that its conduction is governed by the thermally activated ion hopping process. The hopping distance of ions in the PEI decreases from 5.69 nm at 50 °C to 3.34 nm at 100 °C due to the increase of chain motion with the increase of temperature. The activation energy for the electrical conduction is 0.74 eV. ©1996 American Institute of Physics.