The single crystal lithium niobate (LiNbO3) thin film bulk acoustic resonator (FBAR) fabricated by Smart Cut TM technology is introduced in this paper. The COMSOL finite element simulation (FEM) software is used to optimize the material and structure of LiNbO3 thin film FBAR in order to achieve high electromechanical coupling coefficient. A highperformance Zcut LiNbO3 thin film is fabricated as the piezoelectric layer of the resonator by Smart Cut TM technology. The resulting LiNbO3 thin film bulk acoustic resonator has a resonant frequency of 3 847.5 MHz and an antiresonant frequencies of 3 986.25 MHz, an insertion loss of 1.81 dB, and an effective electromechanical coupling coefficient of 8.3%.