Abstract: In this paper, graphics processing unit (GPU)-accelerated finite-difference time domain (FDTD) is developed to expedite the calculation of bistatic scattering coefficient of a two dimensional (2D) rough surface. The formulae and computation model are introduced, respectively. The FDTD lattices are truncated by a uniaxial perfectly matched layer (UPML). The implement of GPU-based FDTD for calculation of electromagnetic scattering from a 2D rough surface is discussed in detail, and the calculation process is also given. Finally, speedup of 50.7×is obtained on NVIDIA GeForce GTX 570 GPU after optimization. The proposed parallel FDTD algorithm improves the computational efficiency greatly.