As the third generation of synthetic flouroquinolone antibacterials, the ofloxacin is a potent antifungal agent with a broad antifungal spectrum, a strong antibacterial activity, the ability of completely oral absorption,a wide distribution in tissue and a high bioavailability. By using the nitric acid to treat multi-walled carbon nanotubes (MWNTs) under the microwave irradiation, the carboxyl groups were introduced onto the MWNTs and the oxidized MWNTs (MWNTs-COOH) were prepared. Catalized by the p-toluenesulfonic acid, the poly(ethylene glycol) modified MWNTs (PEG-g-MWNTs) with good dispersivity were synthesized. The PEG-g-MWNTs composites were used as the drug delivery for drug loading/releasing of the ofloxacin. It is indicated that the PEG-g-MWNTs has a great load rate (92.8%) for the ofloxacin, which can be sustained, controlled and released in the phosphate buffer solution (pH=7.4) in 24h.