||Fluorescent conjugated polymers are being extensively investigated for their potential applications in the fields of optoelectronics, and chemical and biological sensors. Especially, interests in conjugated polymers are rapidly growing because of their unique optoelectronic properties. They have remarkable efficiency of signal amplification compared with corresponding monomer. Since most anions are found in aqueous media, water-soluble polymers are required for anion sensing. Among the various anions, cyanide ion is highly toxic, which affects both in physiological and environmental systems. Thus detecting cyanide ion in water has become a topical object. Cyanide ion sensors based on organoboron receptors have rarely been investigated, in spite of the strong B-CN bonding nature. Several organoboron compounds showing high affinity for cyanide are known. Herein, we synthesis and characterize highly selective fluorescent chemosensor for cyanide ion that can apply in a aqueous solution.