To prepare self-decontamination materials with highly reactive chemical species, such as radicals, the benzophenone chromophoric group branched polymer was synthesized by Friedel-Crafts acylation of polystyrene with benzoyl chloride. The resultant polymer could be prepared into a casting film, and the polymer solution and film were characterized by FTIR, NMR, UV-VIS, XRD, and DSC. From the analyses, it was verified that the benzophenone chromophoric group branched polymer was successfully prepared, and the resultant polymer revealed radical reactivities such as antibacterial effect and decoloration of dye, under UV irradiation.