Abstract: Based on the soil-water characteristic curve of synthetic MSW, quantitative relations between unsaturated conductivity and void ratio/organic content of MSW are given. The relations between unsaturated conductivity and suction in two logarithms coordinates are shown to be linear. The larger the void ratio, the larger the unsaturated hydraulic conductivity and unsaturated gaseous conductivity. The unsaturated hydraulic conductivity is 10^-11~10^-5 cm/s, and the unsaturated gaseous conductivity is 10^-5~10^-2 cm/s. The void ratio has more serious influence on unsaturated conductivity compared to the organic content. The experimental results are proved reasonable by validation, and the unsaturated conductivity of certain MSW can be predicted by the proposed method.