Two new hyperbranched fluorescent conjugated polymers containing pyridine units were synthesized via Heck coupling reaction and Sonogashira coupling reaction, respectively, and characterized by (1)H NMR, (13)C NMR, FTIR, and GPC. The copolymers are readily soluble in common organic solvents such as chloroform, THF, and DMF. Thermal analysis revealed that the copolymers had good thermal stability. The fluorescence quenching behaviors of the hyperbranched copolymers by metal ions were studied. It was found that the fluorescence of the copolymers can be effectively quenched by Pd(2+). Moreover, the two hyperbranched copolymers exhibited different quenching efficiency, which may be related to difference in the hindrance for the chelation of pyridine unit with metal ions of the two polymers. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 121: 217-225, 2011