To satisfy the requirements of alumina castables in specific environment and enhance their properties, alumina castables were prepared using tabular alumina, various alumina powders (07RAL, 15RA, 22RABL, 40CA, 99-20um, and 99-325mesh), and calcium aluminate cement as main raw materials, and heat treating at 110, 1 000, 1 600 ℃, respectively. Their flowability and physical properties were tested, and the morphology was researched. The results show that compared with calcined alumina and tabular alumina powders, reactive alumina has higher specific surface area and better filling performance leading to lower water demand and higher viscosity, and the castables prepared with reactive alumina have higher CCS and CMOR after heat treating at 110, 1 000 and 1 600 ℃ as well as lower PLC than those with calcined alumina and tabular alumina powders.