The chemical reactions of halogen molecules on a nano-graphite cluster are calculated using a semi-empirical calculational method. A real time calculation of the chemical reaction of halogen molecules up to 200 fs which is performed by the dynamic reaction coordinates (DRC) method of the quantum chemistry library shows that the iodine molecule exhibits a special reaction involving the removal of hydrogen atoms from edge carbon atoms. This result might be relevant to recent experiments on the graphitization of pitch at a low temperature of 400°C. We discuss the deformation of the nano-graphite cluster upon the intercalation of halogen atoms.