Light-weight magnesium-aluminate spinel materials were prepared by foaming-gel process with polyaluminium chloride (PAC) as gel. Effect of solid loading in initial slurry on microstructure, porosity, pore size distribution, thermal conductivity and mechanical properties was investigated. The results show that the bulk density of the light-weight magnesium-aluminate spinel materials is in the range of 0.7-1.2 g·cm^-3; pore size distribution curves show single-peak characteristics and the mean pore size is in the range of 30.83-61.37 μm; with the increase of solid loading, the linear shrinkage of the green body during firing and the permanent change in dimensions on heating at 1 600 ¡æ for 3 h decrease, but the bulk density increases, the mechanical properties increase obviously; the maximum compressive strength and bending strength reach 35.25 MPa and 9.92 MPa, respectively, while the bulk density is 1.16 g·cm^-3; and the thermal conductivity at 1 000 ¡æ reaches 0.371 W·m^-1·K^-1 while the bulk density is 0.7 g·cm^-3.ª¤