Abstract: A two-dimensional axisymmetrical model is presented for the medeling and analysis of processes within the cylinder of direct injection died engines,and a computer program RESD-2D is devised. The SGS turbulent model is employed.The fuel spray is simulated by an evaporating liquid spray model,and an ignition delay model is added to simulate the ignition.The combustion and emission are computed by the method of partial equilibrium flow.The above scheme has been applied in the study of the direct injection diesel engine 12150L and the computed results are in good agreement with experimental findings.