In this paper, we simply describe the hardware architectures and properties of modern graphics processing units (GPUs). The GPUs’ applications on mechanics are presented. We have described the fundamental theories and methods on how to accelerate the computations on such mechanical problems as fluid simulation, finite element method, molecular dynamics, quantum Monte Carlo model, and gravitational N-body simulation with GPUs as co-processors. The limitations of general purpose computation on GPUs are analyzed. At last, we have presented the future work on mechanics using GPUs as co-processors.