The 0.95(K0.5Na0.5NbO3)-0.05Li(Nb0.5Sb0.5)O-3 doped with 0.8 mol% copper oxide (CuO) lead-free piezoelectric ceramics were synthesized by conventional solid-state reaction route. The introduction of CuO could significantly improve the sinterability of 0.95(K0.5Na0.5NbO3)-0.05Li(Nb0.5Sb0.5)O-3 ceramics. The grain size of the specimen was considerably decreased due to the formation of a large amount of liquid phase when the sintering temperature exceeded 960 degrees C. The piezoelectric constant (d(33)), planar electromechanical coupling (k(p)), and dielectric constant ( ) values increased with increasing relative density and grain size. The improved piezoelectric and dielectric properties of d(33)=207 pC/N, k(p)=44%, tan delta=0.0137, Q(m)=320, and =340 can be obtained for specimens sintered at 960 degrees C for 2 h.