(Na0.5K0.5)(1-x)LixNbO3 powders and ceramics were prepared by molten salt synthesis method. Pure perovskite-phase powder was obtained at a low temperature of 740 degrees C with a grain size of below 800 nm. The effects of the LiNbO3 on phase transition, microstructure, electrical properties, and temperature stability were investigated. A morphotropic phase boundary was identified. The scanning electron microscopy indicated that the (Na0.5K0.5)(1-x)LixNbO3 powders and ceramics obtained by the molten salt synthesis method have a relatively uniform particle size and microstructure. The results indicate that these materials are promising candidates for lead-free piezoelectric ceramics for practical applications.