In high-pressure diesel engine, the injected fuel spray impinges on the piston cavity surface due to the short distance between the injection nozzle and the cavity wall. The behavior of the impinging spray has the great influence on the dispersion of fuel, the evaporation, and the mixture formation process. In this study, the numerical simulation using the GTT code was performed to study the gas flows, the spray behaviors, and the fuel vapor distributions in the combustion of a D.I engine for variation of spray angle and swirl ratio.