In this work, PEGylated chitosan derivatives were prepared and used to modified poly(ethylene terephthalate) (PET) fabrics. PET fabrics surface were etched by oxygen plasma before different concentrations PEGylated chitosan derivatives solution treatment. The effects of oxygen plasma and PEGylated chitosan derivatives on the surface properties of PET fabrics are investigated by Fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis (TG) and differential scanning calorimetry (DSC). Surface wettability was monitored by water contact angle measurement and moisture regains. The results showed that the occurrence of oxygen-containing functional groups (i.e., CO, CO, and OH) of the plasma-treated PET and the surface coarseness increased from those of the untreated one. There was a layer film formed on the surface of PET fabrics after PEGylated chitosan modification. The combination treatment of oxygen plasma with PEGylated chitosans lightly lowered the breaking strength and elongation of PET fabric. That moisture regains increased and the contact angle decreased implied the hydrophilicity enhancement for the PET fabrics. In addition, dyeing property of PEGylated chitosan derivative modified PET was improved. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39693.