49　metalloporphyrins　were　designed　and　synthesized,　and　9　quantum　chemical　parameters　of　them,　such　as　geometric　structure,　charge　distribution　and　the　frontier　molecular　orbital　etc,　were　calculated　by　using　density　functional　method.　Using　the　catalytic　oxidation　of　o-nitrotoluene　to　o-nitrobenzaldehyde　as　a　model　reaction,　effect　of　metalloporphyrin　structures　on　the　selectivity　of　o-nitrobenzaldehyde　was　investigated.　Main　factors　that　affected　the　selectivity　were　found　out　via　stepwise　regression　analysis　method,　and　a　quantitative　structure-selectivity　relationship　equation　was　effectively　established.　Results　showed　that　the　Mulliken　charge　and　the　electrostatic　potential　of　metal　ions,　the　energy　of　the　lowest　unoccupied　molecular　orbital　were　the　main　factors　affecting　the　selectivity　of　o-nitrobenzaldehyde.　This　equation　could　be　used　to　provide　a　theoretical　guidance　to　design　metalloporphyrins　with　high　selectivity.　©　All　Rights　Reserved.