For the modification of poly(ethylene terephthalate) (PET) fabric, a type of epoxy compound, glycerol polyglycidyl ether (GPE), was impregnated as a cross-linking agent into PET fabric by means of supercritical carbon dioxide (scCO(2)), then, a series of immobilization processes were implemented, including the pad-dry-cure process and the solution process to finish the GPE-PET fabric with natural functional agents (sericin, collagen, or chitosan). Chloroform was found to be an effective cosolvent, as evidenced by the mass transfer of GPE to PET during the treatment with scCO(2). Chemical analyses by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy showed that GPE can penetrate the surface of the PET fabric in scCO(2) pretreatment process, and natural functional agents (sericin, collagen, or chitosan) can also be immobilized on the surface of the GPE-PET fabric especially for the method of pad-dry-cure. The nitrogen content in the modified PET fabrics was calculated accurately and confirmed by combustion analysis. The modified PET fabric displayed improvements in surface wettability, moisturization efficiency, and antibacterial characteristics against S. auretts, which demonstrated that the feasibility of this design for immobilizing natural functional agents (sericin, collagen, or chitosan) onto the surface of the PET fabric. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117: 1897-1907, 2010