The fluorescence and absorption spectra were applied for studying the interaction of 1-bromo ethyl benzene——a component in initiation systems of ATRP and some amino ligands which were used for the copper(I) complex formation．It was found that when the 2,2'-bipyridyl was used as a ligand for metal complex formation,an abnormal new peak was observed obviously whether in fluorescence or absorption spectrum．It indicated that a new species was formed owing to the reaction between them．However,when the aliphatic amines such as tetra methylethylene-diamine and pentamethyldiethylene-tfiamine were used,especially the molar ratio of metal/ligand of complex is 1/4,an evident exciplex emission can be observed in the spectrum．All of these phenomena,especially the chemical reaction occurred in the bipyridyl system will result in unfavorable effects for the ATRP process．And the exciplex formation which was occurred in excited state in aliphatic amine systems will not affect the ATRP process as serious as salt formation in the system of bipyridyl．