In this paper,the effects of quality of gangue amount ofCaO added and w/c ratio upon the weight loss rate and potential of steelas well as pH value and structure of concrete cover of gangue concreteare analysed by means of mercury intrusion porosimetry,scanning electronmicroscopy,pH value measurement and soak-dry cycling.The results ofthis study confirm that the gangue concrete with appropriate proportiongives a good protection for steel.