A particulate matter estimation model was established to calculate the particulate retained in diesel particulate filter with consideration of catalytic reaction in filter. The filtration and catalytic regeneration parameters were identified by engine dynamometer test data, including permeability of carrier and activation energy and pre-exponential factors of the NO2catalytic reaction and thermal catalytic reaction. The estimation model was validated under different operation conditions and model error was less than 10%. Analysis based on the catalytic reaction sub-model approved that the weight of catalytic regeneration was increased with the rise of temperature. At 442℃, percentage of regeneration mass in all engine emission was risen to 45.42%. The regeneration during filtration can effectively prolong the active regeneration cycle. After thorough analysis of the model, most of the particulate mass was distributed in cake layer, accounting more than 98%. The particulate mass in deep bed was discrete in five slabs and mass distribution in deep bed was mainly in the first slab. Under different test conditions, the mass in the first slab accounted more than 85%. And the permeability of the first slab was less than half of those of the other slabs. At 272℃, the particulate mass in different slabs remained stable quickly and the second to the fifth slabs were decreased more than 35% at 442℃. Chemical catalytic reaction at high temperature was the reason for decreasing. For the first slab, cake layer can effectively replenish the regeneration mass. After the theoretical analysis and practical verify, the estimation model included NO2 catalytic reaction and thermal catalytic reaction can effectively predict the retained particulate mass in filter.