Based on virtual reality technology, the paper does some researches and developments for virtual grinding system. A friendly human-computer interaction interface and virtual machining environment are programmed with Visual C++ and OpenGL, and their characters of interaction and immersion are embodied completely. Physical model of virtual grinding wheel and mathematical model of contact between abrasive grain and workpiece are built. Take surface grinding as an example, the simulation system is tested. The results show that the simulation system could make operators have a further understanding to chip formation, and the simulation results could reflect realistic surface topography of workpiece. So the simulation system could be used to forecast surface roughness in actual abrasive machining.