We investigate the influence of gate-source/drain(G-S/D) misalignment on the performance of bulk fin field effect transistors(FinFETs) through the three-dimensional(3D) full band Monte Carlo simulator.Several scattering mechanisms,such as acoustic and optical phonon scattering,ionized impurity scattering,impact ionization scattering and surface roughness scattering are considered in our simulator.The influence of G-S/D overlap and underlap on the on-states performance and carrier transport of bulk FinFETs are mainly discussed in our work.Our results show that the on-states currents increase with the increment of G-D/S overlap length and the positions of a potential barrier and average electron energy maximum vary with the G-D/S overlap length.The carrier transport phenomena in bulk FinFETs are due to the effect of scattering and the electric field in the overlap/underlap regime. We investigate the influence of gate-source / drain (GS / D) misalignment on the performance of bulk fin field effect transistors (FinFETs) through the three-dimensional (3D) full band Monte Carlo simulator. optical phonon scattering, ionized impurity scattering, impact ionization scattering and surface roughness scattering are considered in our simulator. The influence of GS / D overlap and underlap on the on-state performance and carrier transport of bulk FinFETs are mainly discussed in our work. results show that on-state currents increase with the increment of GD / S overlap length and the positions of a potential barrier and average electron energy maximum vary with the GD / S overlap length. The carrier transport phenomena in bulk FinFETs are due to the effect of scattering and the electric field in the overlap / underlap regime.