Porous CaZrO3/MgO composites with a uniform three-dimensional (3-D) network structure have been successfully synthesized using reactive sintering of highly pure mixtures of natural dolomite (CaMg(CO3)(2)) and synthesized zirconia powders with LiF additive. Equimolar dolomite and zirconia powders doped with 0.5 wt% LiF were cold isostatically pressed at 200 MPa and sintered at 1100 -1400 degrees C for 2 h in air. Through the liquid formation via LIF doping, strong necks were formed between constituent particles before completion of the pyrolysis of dolomite, resulting in the formation of a 3-D network structure. During and after the formation of the network structure, CO2 was given off to form a homogeneous open-pore structure. The pore-size distribution was very narrow (with pore size similar to 1 mu m), and the porosity was controllable (e.g.,similar to 30%-50%) by changing the sintering temperature. The porous composites can be applied as filter materials with good structural stability at high temperatures.