As sintering temperature increased from 1350 ฐC to 1550 ฐC, linear shrinkage of porous mullite/corundum ceramics increased from 2.6% to 9.5%. And the shrinkage velocity became larger as sintering temperature was above 1450 ฐC. With the increasing of sintering temperature, the interconnection of mullite grains became stronger, thus the linear shrinkage became larger.