(K0.5Bi0.5)TiO3-BiScO3-PbTiO3 ceramics were synthesized by conventional solid-state method. A morphotropic phase boundary (MPB) was confirmed with the aid of structural analysis. Two dielectric anomalous peaks were observed, the one around dielectric maximum temperature (T) due to phase transformation from ferroelectric to paraelectric while the second one could be ascribed to space charges. Furthermore, the existence of space charges also resulted in the independence of T with frequency at low lead composition. A new high temperature piezoelectric ceramic, 0.30(K0.5Bi0.5)TiO(3-)0.30BiScO(3)-0.40PbTiO(3) close to MPB exhibited excellent electrical properties with T-m of 384 degrees C, d(33) of 247 pC/N, k(p) of 38.9%, P-r of 19.41 mu C/cm(2), and E-c of 2.25 kV/mm, indicative of a candidate for high temperature application. (c) 2009 Elsevier Ltd. All rights reserved.