A　TP　(Temperature　Phase)　model　is　presented　to　carry　out　optimization　calculation　for　a　high-pressure　common　rail　diesel　engine.　Temperature　is　the　most　important　parameter　in　the　TP　model.　When　zone　temperature　T＜1500　K,　only　the　soot　precursors　-PAHs　(Polycyclic　aromatic　hydrocarbons)　is　created　and　there　is　no　soot　emission.　When　zone　temperature　T　＞=　1500　K,　PAHs　and　soot　source　terms　(particle　inception,　surface　growth,　oxidation,　coagulation)　are　calculated.　The　TP　model　is　then　implemented　in　KIVA　code　instead　of　original　model　to　carry　out　optimizing.　The　results　of　cylinder　pressures,　the　corresponding　heat　release　rates,　and　soot　with　variation　of　injection　time,　variation　of　rail　pressure　and　variation　of　speed　among　TP　model,　KIVA　standard　model　and　experimental　data　are　analyzed.　The　results　indicate　that　the　TP　model　can　carry　out　optimization　and　CFD　(computational　fluid　dynamics)　and　can　be　a　tool　to　calculate　for　a　high-pressure　common　rail　diesel　engine.