A cyclic monomer, 10-methylene-9,10-dihydroanthryl-9-spirophenylcyclopropane (MDS), and styrene (St) were copolymerized by conventional radical polymerization and reversible addition - fragmentation chain transfer (RAFT) polymerization. In both cases, NMR analyses of the resulting copolymers indicated that the ring-opening polymerization proceeded predominantly to give copolymers containing anthracene units in the main chain. The copolymers having relatively high MDS contents with narrow polydispersity (M-w/M-n < 1.2) were obtained by RAFT copolymerization in the presence of suitable chain transfer agents. Free radical copolymerizations of MDS and commercial monomers, such as 4-vinylpyridine (4VP), acrylonitrile, n-butyl acrylate, and methyl methacrylate, were studied using 2,2'-azobis(isobutyronitrile) as an initiator. The resulting copolymers absorbed light around 260 nm and 330-430 nm, regardless of the nature of the comonomer. Fluorescent peaks of poly(MDS-co-St) were almost the same as those of poly(MDS), whereas poly(MDS-co-4VP) showed an extremely broad peak from 420 to 640 nm with a maximum at 530 nm. These copolymers were thermally stable above 300 degrees C under nitrogen.