A precursor for K-beta-Al2O3 powder has been synthesized by hydrothermal multicomponent coprecipitation method. The precursor for the synthesis was composed of the solid solution of KxNH4(l-x)Al(OH)(2)CO3(X = 0.1885). The effect of calcination temperature on the formation of K-beta-Al2O3 phase was investigated. It is the first attempt to prepare K-beta-Al2O3 powder by a kind of low-cost wet chemical process.