Perovskite-type Yb0.1Ca0.9-xDyxMnO3 ceramics were synthesized by solid state reaction. Their microstructures were characterized and the thermoelectric properties were evaluated between 300 K and 1100 K. Each of sample exhibits single phase with orthorhombic structure. All samples have high relative densities, and their values are between 95% and 97%, which is consistent with the SEM image. The electrical resistivity shows a typical metallic conductivity behavior. Lowest electrical resistivity 2.36 m Omega cm is achieved at room temperature, and the variation of electrical resistivity is not evident in whole measured temperature range. The Seebeck coefficients are negative, indicating an n-type conduction. The highest power factor 310 mu W/(K-2 m) is obtained for the sample with x = 0.02. The thermal conductivity is decreased by the difference in the mass between the Ca2+ and Dy3+ ions, especially in the heavy doped samples. The highest figure of merit is 0.11 at 1069 K for the sample with x = 0.02. (C) 2012 Elsevier Ltd. All rights reserved.