[en] In the present work, (1-x)(0.935Bi_0.5Na_0.5TiO₃-0.065BaTiO₃)-xKNbO₃ (BNT-BT-KN, BNT-BT-100xKN) ceramics with x ranging from 0 to 0.1 were prepared by the conventional ceramic fabrication process. A large electrostrictive coefficient of ∝10^-2 m⁴ C^-2 is obtained with the composition x ranging from 0.02 to 0.1, which is close to the well-known electrostrictive material Pb(Mg_1/3Nb_2/3)O₃. Under an electric field of 4 kV/mm, the electrostrictive strain can reach as high as 0.08%. Besides, the electric field induced strain behavior indicates a temperature independent behavior within the temperature range of 20 to 150 C. The large electrostrictive strain is suggested to be ascribed to the formation of non-polar (NP) phase developed by the KNbO₃ substitution, and the high electrostrictive coefficient of BNT-BT-KN ceramics makes them great candidates to be applied in the new solid-state actuators. (orig.)