Novel amphiphilic fluorescent graft copolymer （PVP-PyAHy） was successfully synthesized by the free radical copolymerization of hydrophobic monomer N-（1-pyrenebutyryl）-N＇-acryloyl hydrazide （PyAHy） with hydrophilic precursor polymers of vinyl-functionalized poly（N-vinylpyrrolidone） （PVP） in DMF. The copolymer is amphiphilic and has intrinsic fluorescence. FT-IR, ^1H-NMR, TEM, gel permeation chromatography-multi-angle laser light scattering, UV-Vis spectroscopy and fluorescence spectroscopy were used to characterize this copolymer. The TEM observation shows that the copolymer PVP-PyAHy forms micelles in aqueous solution. Results of fluorometric measurements illustrate that the critical micelle concentration （CMC） value of PVP-PyAHy in aqueous solution is about 0.90 mg/mL. To examine the encapsulation ability of the copolymer in aqueous media, methyl yellow was employed as a model hydrophobic agent. The loading level of the polymer to methyl yellow is 8.8 mg/g. The cytotoxicity assays for Madin Darby Canine Kidney （MDCK） cells shows good biocompatibility of PVP-PyAHy in vitro. These results suggest the potential of this copolymer PVP-PyAHy as drugs delivery carrier and fluorescent tracer.
