Thin diamond wires with smaller steel core, finer abrasives and higher abrasive density are being developed for the wire sawing process in the production of silicon in semiconductor and photovoltaic industry. The use of thinner wires not only increases process efficiency by reducing kerf loss but also improves surface quality by enhancing ductile cutting mechanism in cutting zone. In this paper, a model that considers wire and process parameters is developed to study the cutting depth of abrasives and cutting behaviors during wire sawing process of silicon using thin wires. Simulation results show that when using thin wire with diameter of 100 µm, abrasive size ranging from 40 to 60 µm and abrasive density of 650 pcs/mm2, average cutting depth of abrasives is 0.22 µm and 90.7% of abrasives cutting in ductile mode. It is concluded that material removal shifts from brittle cutting dominance to ductile cutting dominance with the use of thinner wire which results in better sliced surface quality. The proposed model is useful in analyzing of optimal parameters for the wire sawing of silicon wafers.