Abstract (Hf1−xZrx)6Ta2O17 (x=0, 0.1, 0.3 and 0.5) ceramic powders were synthesized by conventional solid-state method. The samples of these ceramics were prepared by pressureless sintering process at 1600°C for 8h in air. X-ray diffraction characterization indicated that all samples were single phase with orthorhombic structure. The thermal diffusivities of the samples from 200°C to 1000°C were characterized by laser flash diffusivity measurement. The thermal conductivities of (Hf1−xZrx)6Ta2O17 decreased with the increase of zirconium content x. Thermal conductivity of (Hf0.5Zr0.5)6Ta2O17 was about 2.75W/mK which was comparable with that of dense partially yttria-stabilized zirconia (∼2.5W/mK).