(1-x)BiScO3-xPbTiO(3) (BS-PT) high temperature piezoelectric ceramics were prepared by traditional solid-state reaction method. Combining X-ray diffraction (XRD) results with piezoelectric results, it was found that the morphotropic phase boundary (MPB) is near x = 0.633. The whole set of material constants, such as elastic (s(ij), c(ij)), piezoelectric (d(ij), e(ij), g(ij), h(ij)), dielectric (e(ij), b(ij)), and electromechanical coupling coefficients (k(ij)) for MPB composition were obtained by the resonance method from room temperature to 450 degrees C. The values of d(33), -d(31), d(15), g(33), and Q(m) for MPB composition at room temperature were 441 pC/N, 117 pC/N, 620 pC/N, 47.3 x 10 x (3) Vm/N, and 28, respectively. Temperature-dependent free dielectric epsilon(T)(ij), elastic s(ij)(T), and electromechanical coupling coefficients k(ij) for MPB composition were extremely stable from room temperature up to 350 degrees C. The systematical characterization of dielectric, piezoelectric, and elastic coefficients in the wide temperature range (from room temperature to 450 degrees C) may promote the design and application of high temperature piezoelectric sensors and actuators based on BS-PT ceramics. (C) 2012 Elsevier B.V. All rights reserved.