The 2,2-dinitropropyl acrylate-vinyl acetate (DNPA-VAc) copolymer was synthesized by the free radical polymerization in ethyl acetate using azobisiosbutyronitrile as initiator. The effects of molar ratio of monomers, initiator concentration and time on copolymerization were investigated. The structure and properties of DNPA-VAc copolymer were also characterized by FTIR, ¹H NMR, DSC and TG measurements. Results show that the copolymer is obtained with the yield of 72% under conditions of DNPA and VAc molar ratio of 3:1 at 80 ℃ within 8 hours. The glass transition temperature and thermal decomposition peak temperature of the DNPA-VAc copolymer is 59.7 ℃ and 259.1 ℃. It is compatible with RDX and HMX, and thermal stable.