Abstract: Internal Combustion Engine (ICE) working processes modeling method by using CAD/CAE Software is presented. Matters of gas dynamic and heat process modeling in 4-stroke engine by using ANSYS Fluent and ANSYS Steady-State Thermal Software which allows receiving main thermodynamic parameters fields are discussed. Especial attention is paid on the strength analysis method as well as its settings for solving of the task which are connected with internal combustion engine designing.