β-SiAlON reticular porous ceramics (Si6-ZAlZOZN8-Z, Z=2) were prepared with α-Al2O3, AlN and Si as raw materials and Y2O3 as the sintering aid by the foam impregnation method. The influence of the Y2O3 addition (0, 3%, 6% and 9%, by mass) on the microstructure and the properties of the samples was studied. The results show that the Y2O3 addition is conductive to the sintering of samples and the growth of grains. The sample added with 6% Y2O3 has the optimal properties: the apparent porosity of 82.9%, the bulk density of 0.53 g · cm-3, the cold compressive strength of 1.97 MPa, and the residual cold compressive strength of 1.68 MPa after oxidation, which can be used as porous ceramic filters.