Abstract: β-Hydroxyethyl acrylate(HEA)-terminated polyurethane acrylate (PUA) macromonomer was synthesized and its macroporous AB-crosslinked copolymer particles with styrene(St) and a combination of styrene, ethyl methacrylate(EMA) and divinylbenzene(DVB) were prepared by suspension polymerization using n-heptane as a porogen. The SEM showed that synthetical copolymer resin particles of PUA-St-EMA-DVB contained regular and large pores while those of PUA-St copolymer appeared irregular and smaller pores. The results of underwater acoustic property tests showed that the modified PU-EP blend matrix with PUA-St-EMA-DVB copolymer resin particles had better underwater acoustic absorbing performance than those with PUA-St when the mass ratio of each kinds of particles to PU-EP blend matrix was 20 to 100, with this adding amount the average acoustic absorption coefficient of PU-EP blend matrix with PUA-St-EMA-DVB copolymer resin particles increased from 0.25 to 0.81, and the maximum value increased from 0.58 to 0.98.