The effects of oxygen on butadiene-styrene copolymerization initiated with n-BuLi were studied in this paper.The number of reactive species were investigated by the methods of polymerization kinetics and molecular weight.It was found that lithium reactive species could be killed by oxygen molecules.One oxygen molecule could kill two lithium reactive species.With the increase of the conversion and the oxygen contents

the number of reactive species decreased.The effects of the second-generation impurities on anionic reactive species and microstructure of copolymers were also introduced.At the same time

the coupling effect of oxygen was found to be obvious.With the increase of the oxygen contents and the reaction temperature

the coupling efficiency increased and the properties of styrene-butadiene copolymers were affected by the coupling efficiency of oxygen.With the increase of the coupling effect of oxygen

the vulcanized rubber could may exhibit an increased rolling resistance and a reduced wear resistance.