A fluorescent conjugated polymer was synthesized by the polymerization of 1,4-dibromo-2,3-bisbutoxy naphthalene (M-2) with 5,5'-divinyl-2,2'-bipyridine (M-3) via Heck reaction. The conjugated polymer shows strong blue-green fluorescence because of the extended pi-electronic structure between the repeating unit 2,3-bisbutoxy naphthyl group and the conjugated linker 2,2'-bipyridyl (bpy = 2,2'-bipyridine) moiety via vinylene bridge. The responsive properties of the conjugated polymer on transition metal ions were investigated by fluorescent and UV-vis spectra. The results show that Cu2+ and Ni2+ can form nonradiative metal-to-ligand charge-transfer complexes with the polymer, whereas, Zn2+ and Cd2+ do not produce the pronounced differences from the polymer fluorescence and UV-vis spectra. The fluorescent quenching can probably be attributed to the intramolecular photoinduced electron transfer (PET) or photoinduced charge transfer (PCT). The results can also suggest that 2,2'-bipyridyl moiety in the main chain backbone of the conjugated polymer can act as the recognition site of a special fluorescent chemosensor for sensitive detection of transition metal ions. (D 2008 Wiley Periodicals, Inc. J Appl Polym Sci 111: 3137-3-143, 2009