A comprehensive cycle simulation was developed to predict the performance of gasoline engine including intake and exhaust systems with variation of operating conditions and design factors. In this study, the gas exchange model, compression and expansion model, two-zone combustion model and heat transfer model were used. In order to confirm the feasibility of the simulation program, the calculated results were compared with experimental results. P-$ heta$ diagrams, I. M. E. P. and S. F. C by means of calculation showed acceptable quantitative agreement with the experimental data. Therefore, this program is particularly well adapted to indicating the direction of the optimal design and optimal operating conditions for gasoline engine.