Benzoxazine monomer with methacrylate functionality, namely 2-(2-(2H-benzo[e][1,3]oxazin-3(4H)-yl)ethoxy) ethyl methacrylate (BEM) was synthesized by simple esterification reaction of hydroxyl containing benzoxazine (B-OH) with methacryloyl chloride, and characterized. BEM was then copolymerized with styrene in 1:4 mol ratio by free radical polymerization using 2,2'-azobis(isobutyronitrile) (AIBN) as initiator. The structure, chemical composition, and molecular weight characteristics of the resulting copolymer were confirmed by FT-IR, H-1-NMR spectroscopy, and GPC, respectively. The curing behavior and thermal properties of both monomer and copolymer were also studied by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA).