o-Nitrobenzaldehyde　(ONBD)　is　an　important　intermediate　for　preparing　medicine　and　fine　chemicals.　But　there　are　serious　problems　in　present　industrial　production　methods,　such　as　environmental　pollution,　equipment　corrosion,　and　high　energy　consumption.　A　novel　green　synthesis　of　o-nitrobenzaldehyde　by　dioxygen　oxidation　of　o-nitrotoluene　(ONT)　with　metal　porphyrins　as　catalysts　was　investigated　in　order　to　solve　the　above　problems.　The　results　showed　that　conversion　of　o-nitrotoluene　was　up　to　47.8%,　and　the　maximum　selectivity　and　yield　of　o-nitrobenzaldehyde　were　54.2%　and　25.9%　respectively　under　the　optimum　conditions:　2.0　×　10-6　mol·L-1　of　T(o-Cl)PPZn　catalyst,　5.0　mol·L-1　of　NaOH　concentration,　and　40°C,　1.5　MPa　for　4　h.　The　effects　of　center　metal　ions　and　substituents　as　well　as　their　positions　in　the　ring　of　porphyrin　on　the　activity　and　selectivity　of　the　above　reaction　were　also　studied,　and　the　results　showed　that　center　metal　ions　and　substituents　as　well　as　their　positions　in　the　ring　of　porphyrin　had　very　different　effects　on　the　activity　and　selectivity　of　such　a　reaction.