This study introduced the polymeric drug using methoxy poly(ethylene glycol)p-nitrophenyl carbonate(PEG) and Norfloxacin(NFx). PEG is pharmaceutical application because of its non-immunogenicity and non-toxicity. And the most important feature of PEG modification is that it greatly extends the half-life of drug. The NFx, and of natibiotic agents, has aroused much interest because of its potency and efficacy. However, these low molecular weight antibacterial agents have a lot of disadvantages such as burst of drug, side effects, etc. But polymeric drugs have a lot of advantages such as delayed action, prolongation of activity, ease of manipulation of drugs by getting them to the targeted organism the right amounts at the right time and reduction of side effects. In this study, we synthesised NFx from 1-ethyl-6-fluoro-7-chloro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid piperazine. PEG-NFx was synthesised by dialysis method. It's structure was characterized by FT-IR spectrum and FT ¹H-NMR spectrum.