To obtain a fluorescent polymer having fluorescent groups and thereby enabling detecting a composition containing the polymer by a fluorescence method by copolymerizing an ethylenic unsaturated monomer with a fluorescent compound.

(A) One or more ethylenic unsaturated monomers are copolymerized with (B) a fluorescent compound selected from multinuclear aromatic hydrocarbons and their substituted aromatic derivatives to produce a fluorescent polymer having fluorescent groups. The component B is preferably selected from naphthalene, anthracene, phenanthrene, etc. The copolymerization of the components A and B with (C) an ethylenic unsaturated monomer having a pendant fluorescent functional group can give a coating composition containing the fluorescent polymer and improved in UV light resistance. Thereby, the fluorescent polymer can be used as a marker for identifying the product.