A new method of graft copolymerization of acrylamide(AAM)on poly(etherure-thane) (PEU) which was prepared from poly(oxytetramethylene) glycol (PTMG)，4，4’-diphenylmethane diisocyanate(MDI) and ethylene diamine(E) or butanediol(B) extender was investigated．Hydroperoxide group was first introduced onto the surface of poly(ether-urethane) through photo-oxidation in the presence of hydrogen peroxide，then it was reacted with ferrous ion or N，N-dimethyl toluidine (DMT) to initiate AAM graft copolymerization on PEU surface．The graft reaction COuld be carried out at low temperature with high speed．The grafted PEU film became opaque and its water absorption increased．The forma tion of graft copolymer has been verified by its water absorption ％ and the scanning electron microscopy photographs．Some model compounds of PEU soft segment and hard segment were synthesized in order to clarify the graft reaction mechanism．The results of oxidation and graft copoly-merization of model compounds showed that this graft copolymerization possesses higher selectivity，and it takes place predominately in polyether segment because the ether linkage in soft segment is very sensiti；ce to oxidation and can form hydro-peroxide easily．Thus，the grafting site appears to be at a-carbon of the ether linkage．