Abstract: The potential use of coal gangue for landfill liners is presented. The effects of coal gangue on hydraulic conductivity, Cu²⁺ adsorption and leachability are tested. The hydraulic conductivity of coal gangue can reach 1×10^-7 cm/s and the adsorption process occurs rapidly. Meanwhile the percentage of Cu²⁺ adsorption on fly-ash is nearly 100%. They have better performance than the traditional clay in anti-seepage capability and anti-fouling property. Consequently, it is concluded that the coal gangue and fly ash can be potential anti-seepage materials for landfill liners.