Abstract: Suspended electroplated diamond wire saws with different sanding positions are used to machine single crystal silicon. The sawing performances of different wires are compared by recording machine time and calculating the efficiency. SEM is used to observe the sanding and wear conditions, and the surface roughness is measured by related instruments. Results show that the density of abrasive grain varies greatly as sanding position changes, while that is the highest when sanding position is close to the center of the launder. It is also found that the cutting efficiency is higher if the wire saw has higher abrasive density. The one with abrasive density of 585 per mm could cut 4.949 mm²/min, 138% higher than that of the compared saw which has abrasive density of 446 per mm and efficiency of 2.158 mm²/min. In addition, there is no big difference on surface quality of silicon wafer machined by wire saws with different abrasive density. The main wear or damage patterns of wire saw are abrasive wear, grain shedding and coating wear and damage.