The possibility of enlargement in water absorption ability of bauxite for its practical use as new inorganic water absorbent was studied. (1) Absorbed water by calcined bauxite is possibly utilized for plant growth. High possibility was demonstrated for material. (2) Rapid heating in calcination in fluidized bed (F. B.) was fond to be more effective than muffle calcination to increase water absorption ability of bauxite. Water amount of uncalcinated bauxite was 35 to 38%. More than half of total moisture (20%) was fund to distribute on the surface of bauxite, which is expected to be utilized for plant growth. The other part of moisture was structured (combined) water in bauxite particles. (3) Rapid calcination bauxite at 700 degreesC in F. B. indicated the highest values of mater absorption, specific surface area and total pure volume, respectively which relate to mater absorption and water preservation ability of bauxite particles. The temperature of 700 degreesC was found as optimum calciantion temperature.