A computer model has been developed to predict diesel engine particulate emission during transients in speed and torque. The computer model consists of a quasi-steady-state engine combustion model, a dynamic engine model, and a dynamic turbocharger model. The model uses information developed from steady-state tests to predict the transient particulate emissions.The computer model accurately predicts engine airflow rate, turbocharger speed, and instantaneous engine equivalence ratio. The fuel consumption given by the model is within 3% of the experimental measurement over the EPA transient cycle. The brake-specific particulate emission during the transient cycle is also accurately predicted by the model. The predicted particulate emission is within 5% of the averaged experimental data over the EPA transient cycle.