The ceramics of dysprosium tantalate (DyTaO4) doping with Al3+ (the doping content are 0, 2, 4, and 6mol%, respectively) are successfully synthesized in this work. The results of transmission electron microscopy (TEM) reveal that the DyTaO4 has the domains within ferroelasticity. The thermal properties indicate that the (AlxDy1-x)TaO4 ceramics have much lower thermal conductivity and better high-temperature phase stability than that of 8YSZ (yttria-stabilized zirconia). The elastic properties imply that the (AlxDy1-x)TaO4 have lower elastic properties than that of DyTaO4. The values of Young's modulus of (AlxDy1-x)TaO4 range from 82 to 135GPa, and the thermal expansion coefficients (TEC) of (AlxDy1-x)TaO4 vary in the range of (6-10)x10(-6)K(-1) when the temperature is below 1200 degrees C.