To　investigate　the　effects　of　the　substituents,　substituent　positions　and　axial　chloride　ligand　on　the　geometric　and　electronic　properties　of　the　iron　tetraphenylporphyrin　(FeTPP),　a　series　of　the　substituented　iron　tetraphenylporphyrins　and　their　chlorides,　FeT(o/p-R)PP　and　FeT(o/p-R)PPCl　(R　=　-H,　-Cl,　-NO2,　-OH,　-OCH3),　were　systematically　calculated　without　any　symmetry　constraint　by　using　DFT　method.　For　geometric　structure,　the　substituent　position　and　axial　Cl　ligand　change　the　configuration　of　the　iron　porphyrin　obviously.　The　ortho-substituents　prefer　making　the　phenyls　perpendicular　to　the　porphyrin　ring;　the　axial　chloride　draws　the　central　Fe　ion　similar　to　0.500　out　of　the　porphyrin　plane　toward　the　ligand.　With　regard　to　electronic　properties,　it　is　found　that　E-LUMO　could　be　related　to　the　catalytic　activity.　The　electron-withdrawing　group　always　lowers　the　energies　of　both　frontier　orbitals,　while　the　electron-donating　one　heightens　them　simultaneously,　but　they　affect　the　E-HOMO　and　E-LUMO　in　the　same　sequence,　-NO2　＜　-Cl　＜　-H　＜　-OH　＜　-OCH3.　The　substituent　effects　on　the　central　Fe　ion　were　explored　by　calculating　NBO　charge　distribution,　spin　density　and　natural　electron　configuration.