Photopolymers with both pendant cyclic carbonate groups and cinnamic ester groups were synthesized by the addition reaction of poly(glycidyl methacrylate-co-styrene)[poly(GMA-co-AN)] with carbon dioxide and then with cinnamoyl chloride. Soluble quaternary ammonium salt catalysts showed good yield of cinnamoyl chloride addition to the glycidyl methacrylate groups. Quaternary salt catalysts of longer alkyl chain length and of more nucleophilic anion offered higher yield of cinnamoyl chloride addition. Photochemical reaction test showed that poly(CNMA-co-DOMA-co-St) had a good photosensitivity.