An actuator is a device that converts input energy into mechanical energy. According to various types of input energy, various actuators have been advanced. Displacement in the electromagnetic, hydraulic and pneumatic actuators achieve by moving a piston via electromagnetic force or pressure, however the PIEZOELECTRIC actuator (piezoceramic plates) displace directly. Therefore, accuracy and speed in the PIEZOELECTRIC device are higher than other types of actuators. In the present work, the high-field electromechanical response of high-quality (1−x)(Bi 0.5Na0.5)TiO3–x(Bi0.5K0.5)TiO3 samples abbreviated to BNKTx with x = 0.18, 0.20, 0.22 and 0.24 ceramic materials across its MPB was investigated. The PIEZOELECTRICs and actuation characteristics were characterized. Ourresults indicate that x = 0.20, indeed, constitutes the best choice for the MPB composition in the system. Maximum of remanent polarization (37.5 mC cm-2) was obtained for x=0.20. High-field electromechanical responses were also obtained for BNKT0.20 samples. This material exhibited giant field induced strains of 0.13% under 1 kV mm -1 at room temperature.