(Na0.52K0.44Li0.04)Nb0.9-xSbxTa0.1O 3 lead-free piezoelectric ceramics are prepared by a solid-state reaction method. With increasing Sb content, the transition temperature from orthorhombic to tetragonal polymorphic phase decreased. A composition (Na 0.52K0.44Li0.04)Nb0.863Sb 0.037Ta0.1O3 is found to possess excellent piezo-electric and electromechanical performances (d33 = 306 pC/N, kp = 48%, and kt = 50%), and high Curie temperature (TC = 320°C). These results indicate that (Na 0.52K0.44Li0.04)Nb0.863Sb 0.037Ta0.1O3 is a promising lead-free piezoceramics replacement for lead zirconate titanate. © 2008 Chinese Physical Society and IOP Publishing Ltd.