Novel glucosamine hydrochloride functionalized water‐soluble conjugated polyfluorene was easily synthesized through Cu(I)‐catalyzed azide/alkyne “click” ligation and Suzuki coupling polymerization. The water‐solubility and biocompatibility of the polymer were improved after grafting glucosamine hydrochloride to the side chains of the conjugated polymer. As a fluorescent model system of chitosan, its interaction with single‐stranded DNA was studied by spectrofluorometric titration.