Abstract: Ortho-Iodosocinnamic acid,ortho-iodosophenylacetic acid,and some ortho-lodosobenzoic esters(methyl,ethyl,isopropyl and tcrt-butyl estcrs)werc synthesized.By comparing their IRand NMRspectra with corresponding iodo compounds and iododichlorides,the intramolecular cyclic structure of these compounds was suggested.According to the IRspectra of ortho-,meta-and para-iodosobenzoic acids and esters,and by comparing their relative activities of oxygenalion of cyclohexane catalyzed by TPPFe(Ⅲ)Cl or TPPMn(Ⅲ)C1the intramolecular cyclic structures of ortho-iodosobenzoic acid and ester were suggested,too.This cyclic structure should form partially in meta-iodosobenzoic acid.