(Nd1-xYbx)(2)Zr2O7 (0 <= x <= 1) ceramics were prepared by pressureless-sintering to obtain dense bulk materials. The electrical conductivity of(Nd1-xYbx)(2)Zr2O7 was investigated by complex impedance spectroscopy over a frequency range of 20 Hz to 2 MHz from 723 to 1173 K in air. A high-temperature dilatometer was used to analyze thermal expansion coefficient of (Nd1-xYbx)(2)Zr2O7 in the temperature range of 373-1523 K. The measured electrical conductivity obeys the Arrhenius relation. The grain conductivity of each composition in (Nd1-xYbx)(2)Zr2O7 gradually increases with increasing temperature. A decrease of about one order of magnitude in grain conductivity is found at all temperature levels when the Yb content increases from x = 0.3 to x = 0.5. The highest electrical conductivity value obtained in this work is 9.32 x 10(-3) Scm(-1) at 1173 K for (Nd0.7Yb0.3)(2)Zr2O7 ceramic. (Nd1-xYbx)(2)Zr2O7 ceramics are oxide-ion conductors in the oxygen partial pressure range from 1.0 x 10(-4) to 1.0 arm at all test temperature levels. Thermal expansion coefficients of (Nd1-xYbx)(2)Zr2O7 gradually decrease with increasing ytterbium content at identical temperature levels. (C) 2009 Elsevier B.V. All rights reserved.