This paper aims to enhance the corrosion protection performance of steel pre-treated by zinc phosphate conversion coating (ZPCC) through post-treatment by a hybrid organic-inorganic sol-gel based silane coating (SC) based on the mixture of trimethoxymethylsilane and tetraethyl orthosilicate. The microstructure, surface morphology and chemistry of the ZPCC and ZPCC-SC samples were characterized by X-ray diffraction analysis, atomic force microscopy, scanning electron microscopy, energy dispersive spectroscopy and contact anglemeasuring device. The corrosion protection performance of the bare steel and those treated by ZPCC and ZPCC-SC was evaluated by electrochemical impedance spectroscopy, polarization and salt spray tests. Results showed that deposition of SC on the ZPCC provided a smooth, crack free and dense film with higher water repellency. Results obtained confirmed significant improvement of the ZPCC corrosion resistance after modification by SC. The SC could noticeably enhance the barrier characteristic of ZPCC through filling the porosity of ZPCC and increasing the electrolyte diffusion length. (C) 2017 The Electrochemical Society. All rights reserved.