New bromine-containing oxyphenylimides are synthesized by the Diels-Alder condensation from commercial products. The effect of the bromination of oxyphenylimides on their thermal behavior as comparing with the thermal stability of polystyrene in air is assessed by dynamic thermogravimetric analysis and differential scanning calorimetry. The bromination of oxyphenylimides has different influences on their thermal properties subject to the diene building. The perspectives of the usage of bromine-containing oxyphenylimides for the creation of new polystyrene-stabilizing systems are discussed.