The MPS method has been proven useful in simulating free-surface hydrodynamic flows. Despite its applicability, the MPS method suffers a high computational load. The main objective of this study is to develop a GPU-accelerated MPS code with using CUDA language. Several techniques have been briefly shown to optimize calculations. Some specific three dimensional calculations including a numerical wave flume have been carried out by the GPUaccelerated MPS method. The developed GPU-based code distinctly improves computational efficiency and shows comparable reliability to CPU-based codes.