A simple and effective surface modification of polyester (PET) fabrics with H2SO4 (sulfuric acid) to improve the interfacial deposition of polypyrrole (PPy) on PET fabrics was presented in our work. Effects of H2SO4 concentration on hydrophilicity of PET fabrics were analyzed by water contact angle measurements. Effects of H2SO4 modification on deposition of PPy were investigated by electrical resistivity and color depth of fabrics measurements. Besides, the adhesion of PPy on PET fabrics was also discussed. The PPy-deposited PET fabrics were determined by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). FTIR and XPS results showed that sulfonic acid groups appeared on PET fibers after modification which were contributed to improving deposition of PPy on PET fabrics. The improved deposition increased electrical conductivity of fabrics. (C) 2017 Published by Elsevier B.V.