<p>Electrolysis desaturation is an innovative induced partial saturation technique for liquefaction mitigation, in which pore water electrolysis reduces the degree of saturation of liquefiable sand deposits. To investigate the electrical characteristics and desaturation performance of electrolysis in sand, a series of horizontal electrolysis model tests were conducted on calcareous sands with different gradations and relative densities. The results indicate that the electrical response during electrolysis is strongly influenced by soil gradation and relative density. The potential difference of coarse sand decreased continuously during electrolysis, whereas sand with smaller particle sizes exhibited an initial decrease followed by an increase and eventual stabilization. The saturation exponent n was calibrated for each sand gradation, allowing quantitative estimation of changes in degree of saturation from temperature-corrected resistivity measurements. The influence of relative density on desaturation was strongly dependent on particle size, with fine sand showing higher sensitivity and coarse sand exhibiting a positive correlation between degree of saturation and relative density, in contrast to other sand gradations. For small-span particle-size sands, increasing particle size enhanced the desaturation effect, whereas for large-span sands, more complex gradations led to improved desaturation performance. Power consumption analysis revealed systematic variations with gradation and particle-size span, facilitating estimation of energy requirements and treatment costs for practical applications.</p>