The　peroxynitrite/porphyrin　biomimetic　system　was　established　to　investigate　the　effects　of　peroxynitrite　on　benzo[a]pyrene　(B[a]P)　metabolism.　Three　model　systems　consisting　of　different　iron　porphyrins　were　compared,　and　the　results　showed　that　the　peroxynitrite/T(p-Cl)PPFeCl　system　was　the　highest　catalytic　efficiency　in　the　metabolism　of　B[a]P.　We　analyzed　the　B[a]P　metabolites　produced　from　this　system　by　RP-HPLC　method　and　firstly　identified　the　formation　of　nitrobenzo[a]pyrenes　which　are　the　special　metabolites　of　B[a]P　induced　by　peroxynitrite.