In this study, the effect of the processing parameters in PVD process on the size and the distribution of deposited Si quantum dots was quantitatively investigated by computational simulation utilizing Monte Carlo method. The processing parameters, substrate temperature, deposition time, gas pressure and target-substrate distance were selected as variables since those parameters are often selected as variables in PVD experiments. It is predicted that the density of $1{ imes}10^{12}cm^{-2}$ Si quantum dots can be deposited on the substrate when the deposition rate is 0.05 nm/sec at the substrate temperature of 490${circ}$, deposition time of 7 sec, gas pressure of 3 mTorr and target-substrate distance of 8 cm.