A piezoelectricceramicmaterial having low dielectric constant, high thickness coupling factor, high mechanical quality factor, high stability, and high operating temperature, has been prepared from PbTiO 3 incorporated with 2.5 mol% of LaO 1 2 and 1.0 mol% of MnO 2 . Typical electromechanical constants of this material are as follows: dielectric constant ε 11 T /ε 0 230, ε 33 T /ε 0 170 ; coupling factor k 33 0.46, kt 0.46, k 15 0.28, kp 0.07, k 31 0.04; mechanical quality factor Q 1100, Poisson's ratio σ E 0.20. Frequency constants Nt and N 3t of the fundamental and third‐harmonic thickness vibrations have temperature coefficients of −1.1 × 10−4°C−1 and −2 × 10−5°C−1, respectively. Aging rates of Nt and N 3t , are +0.02% and −0.02%/time decade at 30°C, respectively. The Curie point of this material exists at 470°C, and k 33 and kt increase gradually with temperature up to 400°C. This material has grain size of 2–3 μ and bending strength of 2 × 107 kg/m2, and can be polished into very thin plate. The PbTiO 3 ceramics have a high potential for use in electromechanical devices at high frequency and high temperature.