A 3D profiler based on scanning white light interferometry with a lateral sampling interval of 0.11μm was introduced to measure the surface topography of a #3000 diamond grinding wheel, and a large sampling area could be achieved by its stitching capability without compromising its lateral or vertical resolution. The protrusion height distribution of diamond grains and the static effective grain density of the grinding wheel were derived, and the wheel chatter and the deformation of the wheel were analyzed as well. The study shows that the grain protrusion height obeys an approximate normal distribution, the static effective grain density is much lower than the theoretical density, and only a small number of diamond grains are effective in the grinding process with fine diamond grinding wheel. There exists waviness on the grinding wheel surface parallel with the wheel cutting direction. The cutting surface of the grinding wheel is not flat but umbilicate, which indicates that the elastic deformation at the wheel edges is much larger than in the center region.