The poly(ethyleneglycol) (PEG)-grafted styrene (St) copolymer, which was formed as a nanosphere, was used as an agent to modify the surface of poly(ethylene terephthalate) (PET) film. The graft copolymer was dissolved into chloroform and coated onto the PET film by dip-coating method. The coated amount depends on the content ratios of PEG and St, the solution concentration, and the coating cycles. The graft; copolymers having a low molecular weight of PEG- or St-rich content was fairly stable on washing in sodium dodecyl sulfate (SDS) aqueous solution. It was confirmed that the PET surface easily altered its surface property by the coating of the graft copolymers. The contact angles of the films coated with the graft copolymers were very high (ca. 105-120 degrees). The coated film has good antistatic electric property, which agreed with PEG content. The best condition of coating is a one-cycle coating of 1% (w/v) graft, copolymer solution. The coated surface had water-repellency and antistatic electric property at the same time. The graft copolymer consisted of a PEG macromonomer; St was successfully coated onto PET surfaces, and the desirable properties of both of PEG macromonomer and PSt were exhibited as a novel function of the coated PE film. (C) 1999 John Wiley & Sons, Inc.