Mixing characteristics of a Direct-Injection engine with liquefied petroleum gas were numerically investigated using a 3D unsteady Eularian-Lagrangian two-phase model. Numerical results were validated to the experimental data of heat release rate, pressure and mass flow rate of air. The numerical results and experimental data were in a good agreement. Simulations were conducted with various engine operation conditions to investigate the effects of supercharging on the mixing characteristics of the DI engine with LPG. The results showed that the fuel uniformities and evaporation rates of LPG are higher than them of gasoline. Fuel consumption rates and maximum cylinder temperatures of LPG were also higher than them of gasoline.