Reaction of recoild38Cl atoms with o-dichlorobenzene in the presence of carbon tetrachloride or iodine has been studied by using radio-high performance liquid chromatography. The major products were detected by a 4-channel-wavelengths spectrophotometric detector. The radioactivity of38Cl compounds including minor products was measured with a NaI(T1) scintillation detector. The main products found were38Cl labeled HCl/Cl2, CHCl3, CCl4, o-, p-, m-C6H6Cl2 and polymer, whereas only minor products such as HCl/Cl2, CHCl3, C2Cl6, C6H3Cl3, and polymer were found in the radio-chromatogram. The reaction mechanisms of recoil38Cl atom are briefly described.