A novel method for synthesis of substituted mu-oxo-bis[tetraphenyl porphyrinatoiron] compounds ([TRPPFe](2)O) based on the reaction among free base porphyrins (TRPPH2), FeSO4 center dot 7H(2)O and H2O in one pot was proposed and investigated. Four kinds of [TRPPFe](2)O were synthesized by this novel synthetic method, and their structures were characterized by elemental analysis, infrared spectra and UV-vis spectroscopy. The reaction conditions, including the effect of different iron salts on the formation of [TRPPFe](2)O, the reaction time between FeSO4 center dot 7H(2)O and TRPPH2, the molar ratio of FeSO4 center dot 7H(2)O/TRPPH2 as well as the volume ratio of H2O/DMF, were investigated. The [TRPPFe](2)O yield of 93%-98% could be obtained under the following optimal conditions: the reaction time of FeSO4 center dot 7H(2)O with TRPPH2 was about 10 h, the molar ratio of FeSO4 center dot 7H(2)O/TRPPH2 about 5 : 1, and the volume ratio of H2O/DMF exceeded 2 : 1. Further research indicated that only TRPPFeCl were formed once FeSO4 center dot 7H(2)O was replaced by FeCl2 center dot 4H(2)O, the reason of which might be that halogen ions in iron salts interfered the formation of [TRPPFe](2)O, suggesting that halogen ions should be avoided in this novel synthetic method.