The catalytic oxidations of several cycloolefins in CH2Cl2 were been investigated using Mn(III)-, Fe(III)-porphyrin complexes as a catalyst and sodium hypochlorite as a terminal oxidant. Porphyrins were (p-CH3O)TTP, (p-CH3)TTP, TPP, (p-F)TPP, (p-Cl)TPP and (F20)TPP (TPP = tetraphenylporphyrin), and olefins were cyclopentene, cyclohexene and cycloheptene. The substrate conversion yield was discussed according to the substituent effects of metalloporphyrin. The conversion yield of substrate by changing the substituent of TPP increased in the order of p-CH3O 〈 p-CH3 〈 H 〈 p-F 〈 p-Cl, which was consistent with the sequence of 4Σ values of TPP. The conversion of cycloalkene followed the order of C5 < C6 < C7.