Abstract: Copolymerization of allyl group-capped PEOmacromers with acrylic acid co-monomer to obtain a new type of graft copolymer(PAA-g-PEO) was reported. With the help of model test it is illustrated that the obtained polymer is of the expected structure. A method to determine the composition of copolymer based on IRspectrometry has been set up. Several effects on the copolymerization were examined and the specific solution-behavior was also reported.