The effects of the regeneration parameters such as inlet gas temperature, space velocity, oxygen concentrations in the exhaust gas, and initial particulate loading on the oxidation of the diesel particulates have been experimentally investigated in a steady-state engine experiment. For efficient filter regeneration, at low oxygen concentrations, it is necessary to maintain the inlet gas temperature to over 700 degrees C. However, an abrupt increase in filter temperatures is observed as the oxygen concentrations increase. Safe regeneration can be obtained by increasing the space velocity, however fuel consumption is then increased. Excessive accumulation of the particulate causes undesirable regeneration temperatures inside the filter even under the optimized regeneration conditions. Based on the results from the parametric study, a two-stage regeneration scheme was developed. The results show that this scheme is applicable to over a wide range of engine operating conditions.