The aim of this research was to investigate such geotechnical properties as consistency limits, unconfined compressive strength (UCS), permeability, swelling potential, and the compressibility of slag-based, superfine cement (SSC)-stabilized, high-plasticity clayey soil. LICS ofhigh-plasticity clayey soil was increased by SSC stabilization under both wet-cured and air-dried conditions. UCS values of SSC stabilized specimens under both conditions increased with time. Additionally, UCS values of SSC-stabilized specimens under air-dried condition were higher than those of SSC- stabilized specimens under wet-cured condition. The permeability of high-plasticity clayey soil was reduced by the SSC stabilization, and the permeability of SSC-stabilized soil decreased with time. The swelling potential and the compressibility of high-plasticity clayey soil were also reduced by SSC stabilization.