The Influence of pH on zinc removal ability of blast furnace slag was investigated to use it for the zinc removal agent in landfill cover soil after its termination. Batch type adsorption experiment was performed using washed and no washed blast furnace slag. The adsorption isotherm of Henry type could be applied at pH 8, 9, 12 and 13. A maximum of distribution coefficient was obtained at pH9, 1460L/kg for no washed slag and 265 kg/L for washed slag. No compound to remove zinc would dissolve from slag. Cation coexisting with zinc in leachate had little effect on zinc adsorption of slag. It was found that in actual landfill condition with pH of 7-8, the blast furnace slag would adsorb zinc with lower adsorption ability than the maximum appeared at pH9.