Abstract: The electrolytic desaturation method is an innovative method for mitigation of soil liquefaction in recent years. In this method, the air bubbles produced by electrolysis in the pore water of the saturated sandy foundation can reduce the saturation degree of the soil, and improve liquefaction resistance. In this study, the desaturation model tests on sand foundation under constant current intensity are carried out by using the conductive plastic drainage plates as the electrodes. Besides, the electrical properties of the sand foundation in the process of electrolysis are analyzed. The results show that at the initial stage of electrolytic desaturation process, the decreasing rate of saturation increases linearly with the currency intensity, then the saturation continues to decrease in a gradual decrease rate, and finally the saturation reduces to 89.5%, which is independent of the current intensity. In addition, the equivalent electrical resistance of the foundation increases with the decrease of the saturation of sand. Meanwhile, four kinds of indices including the pore water pressure coefficient B, the gas bearing water bulk modulus K_wa, the compression wave velocity v_p and equivalent electric resistance of foundation are also evaluated here for analyzing the state of desaturation of sand foundation. The results show that the equivalent electric resistance is most easily measured, and has the largest sensitive range of sand saturation. Therefore, the equivalent electric resistance of foundation can be adopted as an effective index to evaluate the state of desaturation of sand foundation.