The finite-dmerence time-domam(FDTD)method is proposed for analyzing the surface acoustic wave(SAW)propagation in two-dimensional(2D)piezoelectric phononic crystals(PCs)at radio frequency(RF),and also experiments are estabhshed to demonstrate its analysis result of the PCs’band gaps.The FDTD method takes the piezoelectric effect of PCs into account,in which periodic boundary conditions are used to decrease memory/time consumption and the perfectly matched layer boundary conditions are adopted as the SAW absorbers to attenuate artificial reflections.Two SAW delay lines are estabhshed with/without piezoelectric PCs located between interdigital transducers.By removing several echoes with window gating function in time domain,delay lines transmission function is achieved.The PCs’transmission functions and band gaps are obtained by comparing them in these two delay lines.When Aluminum/128°YX-LiNbO_3 is adopted as scatter and substrate material,the PCs’band gap is calculated by this FDTD method and COMSOL respectively.Results show that computational results of FDTD agree well with experimental results and are better than that of COMSOL. The finite-dmerence time-domam (FDTD) method is proposed for analyzing the surface acoustic wave (SAW) propagation in two-dimensional (2D) piezoelectric phononic crystals (PCs) at radio frequency (RF), and also experiments were estabhshed to demonstrate its analysis result of of PCs’ band gaps.The FDTD method takes the piezoelectric effect of PCs into account, in which periodic boundary conditions are used to decrease memory / time consumption and the perfectly matched layer boundary conditions are adopted as the SAW absorbers to attenuate artificial reflections.Two SAW delay lines are estabhshed with / without piezoelectric PCs located between interdigital transducers. By ry with window gating function in time domain, delay lines transmission function is achieved. PCs’ transmission functions and band gaps are found by comparing these in these two delay lines. Aluminum / 128 ° YX-LiNbO_3 is adopted as scatter and substrate material, the PCs’ band gap is calculated by this FDTD me thod and COMSOL respectively. Results show that computational results of FDTD agree well with experimental results and are better than that of COMSOL.