In this paper,a study was conducted to investigate the surface grinding of a iron-based diamond segments with an alumina grinding wheel.Vertical and horizontal forces were in-process measured.The characteristics of normal and tangential force components,their ratios and specific energy were subsequently studied for the grinding of the diamond segment.The morphologies of the ground segment surfaces were observed.Two grinding modes-up grinding and down grinding-were compared in the study.It is found that the normal force,tangential force and specific energy for the down-grinding are higher than the up-grinding. But the ratios of tangential force to normal force for the two grinding modes are comparable.