A　novel　green　synthesis　of　o-nitrobenzoic　acid　by　aerobic　oxidation　of　o-nitrotoluene　with　aqueous　ethanol　instead　of　pure　methanol　as　the　solvent　and　substituted　iron　porphyrins　as　biomimetic　catalysts　was　investigated.　The　effects　of　six　iron　porphyrins　with　different　peripheral　substituents　on　the　above　reaction　were　studied.　It　was　found　that　all　iron　porphyrins　had　catalytic　activity,　and　the　substituents　from　strong　electron　donating　group　(-OH)　to　electron　withdrawing　group　(-NO2)　had　a　remarkable　effect　on　the　selectivity　of　o-nitrobenzoic　acid　and　a　insignificant　effect　on　the　activity　(conversion　of　o-nitrotoluene).　Among　the　six　iron　porphyrins　T　(p-Cl)　PPFeCl　had　the　highest　catalytic　activity　and　selectivity　at　the　same　time.　By　introducing　a　stronger　electron　withdrawing　substituent,　such　as　-NO2　or　strong　electron　donating　group,　such　as　-OH　around　the　porphyrin　rings　resulted　in　low　catalytic　activity　and　selectivity.　Moreover,　the　effects　of　different　process　parameters,　such　as　ethanol　concentration,　NaOH　concentration,　dioxygen　pressure,　temperature,　reaction　time　and　initial　concentration　of　o-nitrotoluene　on　the　above　reaction　were　examined,　and　optimal　conditions　were　obtained.　The　conversion　of　o-nitrotoluene,　the　selectivity　and　yield　of　product　could　reach　79.7%,　95.8%　and　76.3%　respectively　by　using　aqueous　ethanol　of　80%　instead　of　pure　methanol　as　solvent　and　T(p-Cl)PPFeCl　as　catalyst,　and　the　reaction　was　carried　out　under　optimal　conditions,　such　as　NaOH　concentration　of　3.75　mol·L-1,　2.0　MPa　O2　at　55°C　for　12　h.