A set of water-soluble dendronized polyfluorenes bearing peripheral charged amino groups were synthesized by two steps: (1) Suzuki polycondensation of dendritic macromonomers carrying peripheral Boc-protected amino groups with 1,4-benzenediboronic acid propanediol ester; (2) the deprotection of the resulting Boc-protected dendronized polymers with aqueous HCl. All the protected dendronized polyfluorenes displayed good solubility in common organic solvents such as THF, chloroform, and methylene chloride. After deprotection, the zero generation polymers were only partially soluble in water, but the first and the second generation dendronized polymers were fully soluble in water. The optic properties of the protected and deprotected dendronized polymers were investigated. In solution, all these polymers exhibited bright blue emission. Unlike normal water-soluble conjugated polymer, the second generation deprotected dendronized polyfluorenes exhibited a quite high quantum yield (Phi(F) = 94%) in water.