Samples of CeO2 doped with oxides such as CaO and Gd2O3 were prepared. Their conductivities and expansions onreduction were measured at 1000°C, and the thermal expansion coefficients in the range 50 to 1000°C were determined. Theionic and electronic conductivity were derived from curves of total conductivity vs. oxygen partial pressure. For both typesof conductivity a dependence on dopant valency was observed. The electronic conductivity was independent of dopantradius in contrast to the ionic which was highly dependent. These measured physical properties are compared with the idealrequirements for solid oxide fuel cell anodes. Not all requirements are fulfilled. Measures to compensate for this arediscussed.