The creating scratch by an abrasive grit is mostly investigated to enhance the finishing processes. In grinding many distributed abrasive grits on grinding wheel surface engaged with workpiece to remove material. To investigate the material removal mechanism in grinding process a scratch and removed material by an abrasive grit is assumed and simulated. The results are developed for all engaged abrasive grits on grinding wheel surface. This leads to improve the machining process and taking a deep sight in to the grinding mechanism. By analyzing a creating scratch by a single abrasive grit, the material removal mechanism is scrutinized in a different view. The effect of grinding wheel surface topography and input parameters on material removal mechanism is investigated. Results show that increasing cutting speed leads to changing material removal mechanism from ploughing to cutting. The shape of abrasive grits has more effect on material removal mechanism. In worn grits increasing the cutting depth cause the ploughing to be dominant mechanism in machining. This leads to less cutting efficiency. But in abrasive grits with sharp single cutting edge the converse results is achieved. When grit breaks down and self dressing occurs during machining, the multiple edges are formed on grit and the grit acts like a dull abrasive.