The electronic conductivity of pure ceria was successfully measured by a dc polarization technique based on the Hebb-Wagner ion blocking method at T=873-1273 K. The electronic conductivity increased with increasing temperature at given P(O-2) values. It also increased with decreasing P(O-2) following slope values of -1/6 to -1/4. At 873-1073 K, no P(O-2) dependent region was observed at higher P(O-2) more than 10(-2), 10(-4), and 10(-5) MPa at 1073, 973, and 873 K, respectively. Activation energies calculated from the Arrhenius plots for those different regions were 2.2, 2.9, and 1.9 eV for P(O-2) dependences of -1/6, -1/4, and 0 regions, respectively.