A new type of gasoline engine that adopts Direction Circularly Stratified-Charge combustion System is developed, and the optimum parameters of the DICSC combustion system are obtained by studying the effects of main parameters such as the nozzle type, the location of fuel spray relative to the spark plug, the fuel delivery advanced angle, the injection valve opening pressure, the air swirl ratio, the plunger diameter and compression ratio. The thermal efficiency of the new gasoline engine is roughly the same as the original diesel engine.